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TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 1 the lumenology company copyright 2011, taos inc. www.taosinc.com features ambient light sensing and proximity detection in a single device ambient light sensing (als) ? approximates human eye response ? programmable analog gain and integration time ? 8,000,000:1 dynamic range ? operation to 60,000 lux in sunlight ? very high sensitivity ? ideally suited for operation behind dark glass ? package uv rejection filter proximity detection ? programmable analog gain, integration time, and offset ? current sink driver for external ir led ? saturation indicator ? 16,000:1 dynamic range maskable als and proximity interrupt ? programmable upper and lower thresholds with persistence filter power management ? low power 2.2 a sleep state with user- selectable sleep-after-interrupt mode ? 90 a wait state with programmable wait time from 2.7 ms to > 8 seconds i 2 c fast mode compatible interface ? data rates up to 400 kbit/s ? input voltage levels compatible with v dd or 1.8-v bus register set- and pin-compatible with the tsl2x71 series small 2 mm 2 mm dual flat no-lead (fn) package applications display backlight control cell phone touch screen disable mechanical switch replacement industrial process control medical diagnostics printer paper alignment end products and market segments mobile handsets, tablets, laptops, hdtvs, monitors, and pmp (portable media players) medical and industrial instrumentation white goods toys industrial/commercial lighting digital signage printers description the TSL2772 device family provides both ambient light sensing (als) and, when coupled with an external ir led, proximity detection. the device family is based on the taos patented dual-diode technology that enables accurate als results and approximates human eye response to light intensity under a variety of lighting conditions. the TSL2772 als includes a reduced-gain mode that extends the operating range to 60k lux in sunlight. the device package incorporates a uv-rejection filter that enables accurate als. the TSL2772 proximity detection includes improved signal-to-noise performance and selectable gain modes. a proximity offset register allows compensation fo r optical system crosstalk bet ween the ir led and the sensor. to prevent false proximity data measurement readings, a proximity saturation indicator bit signals that the internal analog circuitry has reached saturation. texas advanced optoelectronic solutions inc. 1001 klein road suite 300 plano, tx 75074 (972) 673-0759 package fn dual flat no-lead (top view) v dd 1 scl 2 gnd 3 6 sda 5 int 4 ldr not actual size ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 2 copyright 2011, taos inc. the lumenology company www.taosinc.com functional block diagram ch0 sda v dd int scl ldr ch1 adc als control ch1 data wait control prox adc prox control prox data prox led current driver ch0 adc ch0 data prox integration ch1 upper limit upper limit lower limit lower limit interrupt i 2 c interface gnd detailed description the TSL2772 light-to-digital device provides on-chip photodiodes, integrating amplifiers, adcs, accumulators, clocks, buffers, comparators, a state machine, and an i 2 c interface. each device combines a channel 0 photodiode (ch0), which is responsive to both visible and infrared light, and a channel 1 photodiode (ch1), which is responsive primarily to infrared light. two integrating adcs simultaneously convert the amplified photodiode currents into a digital value providing up to 16 bits of resolution. upon completion of the conversion cycle, the conversion result is transferred to the data registers. this digital output can be read by a microprocessor through which the illuminance (ambient light level) in lux is derived using an empirical formula to approximate the human eye response. communication to the device is accomplished through a fast (up to 400 khz), two-wire i 2 c serial bus for easy connection to a microcontroller or embedded controller. the digital output of the device is inherently more immune to noise when compared to an analog interface. the device provides a separate pin for level-style interrupts. when interrupts are enabled and a pre-set value is exceeded, the interrupt pin is asserted and remains asserted until cleared by the controlling firmware. the interrupt feature simplifies and improves system efficiency by eliminating the need to poll a sensor for a light intensity or proximity value. an interrupt is generated when the value of an als or proximity conversion exceeds either an upper or lower threshold. in addition, a programmable interrupt persistence feature allows the user to determine how many consecutive exceeded thresholds are necessary to trigger an interrupt. interrupt thresholds and persistence settings are configured independently for both als and proximity. proximity detection requires only a single external ir led. an internal led driver can be configured to provide a constant current sink of 15 ma, 30 ma, 60 ma, or 120 ma of current. no external current limiting resistor is required. the power can also be reduced by a factor of 8 with the pdl bit. the number of proximity led pulses can be programmed from 1 to 255 pulses. each pulse has a 16-s period. the programmable led current, coupled with the programmable number of pulses, provides a 16,000:1 contiguous dynamic range. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 3 the lumenology company copyright 2011, taos inc. www.taosinc.com terminal functions terminal type description name no. type description gnd 3 power supply ground. all voltages are referenced to gnd. int 5 o interrupt ? open drain (active low). ldr 4 o led driver for proximity emitter ? open drain. scl 2 i i 2 c serial clock input terminal ? clock signal for i 2 c serial data. sda 6 i/o i 2 c serial data i/o terminal ? serial data i/o for i 2 c . v dd 1 supply voltage. available options device address package ? leads interface description ordering number TSL27721 0x39 fn?6 i 2 c vbus = v dd interface TSL27721fn TSL27723 0x39 fn?6 i 2 c vbus = 1.8 v interface TSL27723fn TSL27725 ? 0x29 fn?6 i 2 c vbus = v dd interface TSL27725fn TSL27727 ? 0x29 fn?6 i 2 c vbus = 1.8 v interface TSL27727fn ? contact taos for availability. absolute maximum ratings over operating free-air temperature range (unless otherwise noted) ? supply voltage, v dd (note 1) 3.8 v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . input terminal voltage ?0.5 v to 3.8 v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . output terminal voltage (except ldr) ?0.5 v to 3.8 v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . output terminal voltage (ldr) 3.8 v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . output terminal current (except ldr) ?1 ma to 20 ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . storage temperature range, t stg ?40 c to 85 c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . esd tolerance, human body model 2000 v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ? stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. these are stress ratings only, a nd functional operation of the device at these or any other conditions beyond those indicated under ?recommended operating conditions? is not implied. exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. note 1: all voltages are with respect to gnd. recommended operating conditions min nom max unit supply voltage, v dd (TSL27721 & TSL27725) (i 2 c v bus = v dd ) 2.4 3 3.6 v supply voltage, v dd (TSL27723 & TSL27727) (i 2 c v bus = 1.8 v) 2.7 3 3.6 v operating free-air temperature, t a ?30 70 c ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 4 copyright 2011, taos inc. the lumenology company www.taosinc.com operating characteristics, v dd = 3 v, t a = 25 c (unless otherwise noted) parameter test conditions min typ max unit active ? ldr pulse off 200 250 i dd supply current wait state 90 a i dd supply current sleep state ? no i 2 c activity 2.2 4 a v int sda output low voltage 3 ma sink current 0 0.4 v v ol int, sda output low voltage 6 ma sink current 0 0.6 v i leak leakage current, sda, scl, int pins ?5 5 a i leak leakage current, ldr pin ?5 5 a v scl sda input high voltage TSL27721, TSL27725 0.7 v dd v v ih scl, sda input high voltage TSL27723, TSL27727 1.25 v v scl sda input low voltage TSL27721, TSL27725 0.3 v dd v v il scl, sda input low voltage TSL27723, TSL27727 0.54 v als characteristics, v dd = 3 v, t a = 25 c, again = 16 , aen = 1 (unless otherwise noted) (notes 1 ,2, 3) parameter test conditions channel min typ max unit dark adc count value e e = 0, again = 120 , ch0 0 1 5 counts dark adc count value e e = 0 , again = 120 , atime = 0xdb (100 ms) ch1 0 1 5 counts adc integration time step size atime = 0xff 2.58 2.73 2.9 ms adc number of integration steps (note 4) 1 256 steps adc counts per step (note 4) atime = 0xff 0 1024 counts adc count value (note 4) atime = 0xc0 0 65535 counts white li g ht, e e = 263.9 w/cm 2 , ch0 4000 5000 6000 adc count value white light , e e = 263 . 9 w/cm , atime = 0xf6 (27 ms) (note 2) ch1 680 counts adc count value p = 850 nm, e e = 263.4 w/cm 2 , ch0 4000 5000 6000 counts p = 850 nm , e e = 263 . 4 w/cm , atime = 0xf6 (27 ms) (note 3) ch1 2850 adc count value ratio: ch1/ch0 white light, atime = 0xf6 (27 ms) (note 2) 0.086 0.136 0.186 adc count value ratio: ch1/ch0 p = 850 nm, atime = 0xf6 (27 ms) (note 3) 0.456 0.570 0.684 white li g ht, atime = 0xf6 (27 ms) ch0 18.9 r irradiance responsivity white light , atime = 0xf6 (27 ms) (note 2) ch1 2.58 counts/ ( w/ r e irradiance responsivity p = 850 nm, atime = 0xf6 (27 ms) ch0 19.0 ( w/ c m 2 ) p = 850 nm , atime = 0xf6 (27 ms) (note 3) ch1 10.8 cm 2 ) again = 1 and agl = 1 0.128 0.16 0.192 gain scalin g , relative to 1 g ain again = 8 and agl = 0 7.2 8.0 8.8 gain scaling , relative to 1 gain setting again 16 and agl 0 14 4 16 0 17 6 se tti ng again = 16 and agl = 0 14.4 16.0 17.6 again = 120 and agl = 0 108 120 132 notes: 1. optical measurements are made using small-angle incident radiation from light-emitting diode optical sources. visible w hite leds and infrared 850 nm leds are used for final product testing for compatibility with high-volume production. 2. the white led irradiance is supplied by a white light-emitting diode with a nominal color temperature of 4000 k. 3. the 850 nm irradiance e e is supplied by a gaas light-emitting diode with the following typical characteristics: peak wavelength p = 850 nm and spectral halfwidth ? ? = 42 nm. 4. parameter ensured by design and is not tested. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 5 the lumenology company copyright 2011, taos inc. www.taosinc.com proximity characteristics, v dd = 3 v, t a = 25 c, pgain = 1 , pen = 1 (unless otherwise noted) parameter test conditions min typ max unit i dd supply current ldr pulse on 3 ma adc conversion time step size ptime = 0xff 2.58 2.73 2.9 ms adc number of integration steps (note 1) 1 256 steps adc counts per step (note 1) ptime = 0xff 0 1023 counts adc count value p = 850 nm, e e = 263.4 w/cm 2 , ch0 diode 1500 2000 2500 counts adc count value p = 850 nm , e e = 263 . 4 w/cm , ptime = 0xfb, ppulse = 4 ch1 diode 900 1200 1500 counts adc output responsivity 850 nm ptime 0xfb ppulse 1 ch0 diode 1.90 counts/ adc output responsivity p = 850 nm, ptime = 0xfb, ppulse = 1 ch1 diode 1.14 counts/ w/cm 2 gi li lti t 1 i pgain = 2 2 gain scalin g , relative to 1 g ain pgain 4 4 gain scaling , relative to 1 gain setting pgain = 4 4 se tti ng pgain = 8 8 noise (notes 1 2 3) e e = 0, ptime = 0xfb, ppulse = 4 ch0 diode 0.5 %fs noise (notes 1, 2, 3) e e = 0 , ptime = 0xfb , ppulse = 4 (note 6) ch1 diode 0.5 % fs led pulse count (note 1) 0 255 pulses led pulse period 16.0 s led pulse width ? led on time 7.3 s 120 ma: pdrive = 0 & pdl = 0 87 116 145 60 ma: pdrive = 1 & pdl = 0 58 30 ma: pdrive = 2 & pdl = 0 29 led drive current i s ink sink current @ 15 ma: pdrive = 3 & pdl = 0 14.5 ma led drive current i sink sink current @ 1.6 v, ldr pin 15 ma: pdrive = 0 & pdl = 1 12.9 ma 7.5 ma: pdrive = 1 & pdl = 1 6.4 3.8 ma: pdrive = 2 & pdl = 1 3.2 1.9 ma: pdrive = 3 & pdl = 1 1.6 maximum operating distance (notes 1, 4, 5) pdrive = 0 and pdl = 0 (116 ma), ppulse = 64 emitter: p = 850 nm, 20 half angle, and 60 mw/sr object: 16 20-inch, 90% reflective kodak gray card (white surface) optics: open view (no glass, no optical attenuation) 18 inches notes: 1. parameter is ensured by design or characterization and is not tested. 2. proximity noise is defined as one standard deviation of 600 samples. 3. proximity noise typically increases as ppulse 4. greater operating distances are achievable with appropriate optical system design considerations. see available t aos application notes for additional information. 5. maximum operating distance is dependent upon emitter and the reflective properties of the object?s surface. 6. proximity noise test was done using the following circuit: TSL2772 v dd 1 f 22 15.0 1 34 v dd gnd ldr ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 6 copyright 2011, taos inc. the lumenology company www.taosinc.com wait characteristics, v dd = 3 v, t a = 25 c, wen = 1 (unless otherwise noted) parameter test conditions channel min typ max unit wait step size wtime = 0xff 2.58 2.73 2.9 ms wait number of integration steps (note 1) 1 256 steps note 1: parameter ensured by design and is not tested. ac electrical characteristics, v dd = 3 v, t a = 25 c (unless otherwise noted) parameter ? test conditions min typ max unit f (scl) clock frequency (i 2 c only) 0 400 khz t (buf) bus free time between start and stop condition 1.3 s t (hdsta) hold time after (repeated) start condition. after this period, the first clock is generated. 0.6 s t (susta) repeated start condition setup time 0.6 s t (susto) stop condition setup time 0.6 s t (hddat) data hold time 0 s t (sudat) data setup time 100 ns t (low) scl clock low period 1.3 s t (high) scl clock high period 0.6 s t f clock/data fall time 300 ns t r clock/data rise time 300 ns c i input pin capacitance 10 pf ? specified by design and characterization; not production tested. parameter measurement information start condition stop condition p sda t (susto) t (sudat) t (hddat) t (buf) v ih v il scl t (susta) t (high) t (f) t (r) t (hdsta) t (low) v ih v il ps s figure 1. timing diagrams ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 7 the lumenology company copyright 2011, taos inc. www.taosinc.com typical characteristics ch 1 ch 0 figure 2 spectral responsivity ? wavelength ? nm 0 400 0.2 0.4 0.6 0.8 1 500 600 700 800 900 1000 1100 normalized responsivity 300 figure 3 normalized responsivity vs. angular displacement ? angular displacement ? normalized responsivity 0 0.2 0.4 0.6 0.8 1.0 ?90 ?60 ?30 0 30 60 90 optical axis both axes 15 ma figure 4 ldr voltage ? v ldr current ? ma typical ldr current vs. voltage 0 0.5 1 1.5 2 2.5 0 2 4 6 8 10 12 14 16 3 18 3.8 ma 1.9 ma 7.5 ma 20 30 ma 15 ma 120 ma figure 5 ldr voltage ? v ldr current ? ma typical ldr current vs. voltage 0 0.5 1 1.5 2 2.5 0 20 40 60 80 100 120 140 160 3 60 ma ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 8 copyright 2011, taos inc. the lumenology company www.taosinc.com ch 1 ch 0 figure 6 response to white led vs. temperature 90% 95% 100% 105% 115% 010203040506070 110% temperature ? c response ? normalized to 25 c ch 0 ch 1 figure 7 response to ir (850 nm) led vs. temperature 90% 95% 100% 105% 115% 010203040506070 110% temperature ? c response ? normalized to 25 c figure 8 normalized i dd vs. v dd and temperature v dd ? v i dd ? active current normalized @ 3 v, 25 c 94% 96% 98% 100% 102% 104% 106% 108% 110% 92% 2.7 2.8 2.9 3 3.1 3.2 3.3 75 c 50 c 0 c 25 c ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 9 the lumenology company copyright 2011, taos inc. www.taosinc.com principles of operation system state machine an internal state machine provides system control of the als, proximity detection, and power management features of t he device. at power up, an internal power-on-reset initializes the device and puts it in a low-power sleep state. when a start condition is detected on the i 2 c bus, the device transitions to the idle state where it checks the enable register (0x00) pon bit. if pon is disabled, the device will return to the sleep state to save power. otherwise, the device will remain in the idle state until a proximity or als function is enabled. once enabled, the device will execute the prox, wait, and als states in sequence as indicated in figure 9. upon completion and return to idle, the device will automatically begin a new prox?wait?als cycle as long as pon and either pen or aen remain enabled. if the prox or als function generates an interrupt and the sleep-after-interrupt (sai) feature is enabled, the device w ill transition to the sleep state and remain in a low-power mode until an i 2 c command is received. see the interrupts section for additional information. !pen & !wen & aen !wen & !aen pen sleep idle wait als prox i 2 c start !pon int & sai aen wen int & sai !aen !pen & wen & aen !wen & aen figure 9. simplified state diagram photodiodes conventional als detectors respond strongly to infrared light, which the human eye does not see. this can lead to significant error when the infrared content of the ambient light is high (such as with incandescent lighting). this problem is overcome through the use of two photodiodes. the channel 0 photodiode, referred to as the ch0 channel, is sensitive to both visible and infrared light, while the channel 1 photodiode, referred to as ch1, is sensitive primarily to infrared light. two integrating adcs convert the photodiode currents to digital outputs. the adc digital outputs from the two channels are used in a formula to obtain a value that approximates the human eye response in units of lux. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 10 copyright 2011, taos inc. the lumenology company www.taosinc.com als operation the als engine contains als gain control (again) and two integrating analog-to-digital converters (adc), one for the ch0 and one for the ch1 photodiodes. the als integration time (atime) impacts both the resolution and the sensitivity of the als reading. integration of both channels occurs simultaneously and upon completion of the conversion cycle, the results are transferred to the data registers (c0data and c1data). this data is also referred to as channel count . the transfers are double-buffered to ensure data integrity. ch1 adc als control ch1 data ch0 als ch0 data again(r0x0f, b1:0) 1 , 8 , 16 , 120 gain ch0 ch1 c0datah(r0x15), c0data(r0x14) c1datah(r0x17), c1data(r0x16) atime(r 1) 2.73 ms to 699 ms figure 10. als operation the registers for programming the integration and wait times are a 2?s compliment values. the actual time can be calculated as follows: atime = 256 ? integration time / 2.73 ms inversely, the time can be calculated from the register value as follows: integration time = 2.73 ms (256 ? atime) in order to reject 50/60-hz ripple strongly present in fluorescent lighting, the integration time needs to be programmed in multiples of 10 / 8.3 ms or the half cycle time. both frequencies can be rejected with a programmed value of 50 ms (atime = 0xed) or multiples of 50 ms (i.e. 100, 150, 200, 400, 600). the registers for programming the again hold a two-bit value representing a gain of 1 , 8 , 16 , or 120 . the gain, in terms of amount of gain, will be represented by the value againx, i.e. againx = 1, 8, 16, or 120. with the agl bit set, the 1 and 8 gains are lowered to 1/6 and 8/6 , respectively, to allow for operation up to 60k lux. do not enable agl when again is 16 or 120 . lux equation the lux calculation is a function of ch0 channel count (c0data), ch1 channel count (c1data), als gain (againx), and als integration time in milliseconds (atime_ms). if an aperture, glass/plastic, or a light pipe attenuates the light equally across the spectrum (300 nm to 1100 nm), then a scaling factor referred to as glass attenuation (ga) can be used to compensate for attenuation. for a device in open air with no aperture or glass/plastic above the device, ga = 1. if it is not spectrally flat, then a custom lux equation with new coef ficients should be generated. (see taos application note). counts per lux (cpl) needs to be calculated only when atime or again is changed, otherwise it remains a constant. the first segment of the equation (lux1) covers fluorescent and incandescent light. the second segment (lux2) covers dimmed incandescent light. the final lux is the maximum of lux1, lux2, or 0. cpl = (atime_ms againx) / (ga 60) lux1 = (1 c0data ? 1.87 c1data) / cpl lux2 = (0.63 c0data ? 1 c1data) / cpl lux = max(lux1, lux2, 0) ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 11 the lumenology company copyright 2011, taos inc. www.taosinc.com proximity detection proximity detection is accomplished by measuring the amount of light energy, generally from an ir led, reflected off an object to determine its distance. the proximity light source, which is external to the TSL2772 device, is driven by the integrated proximity led current driver as shown in figure 11. ch1 prox integration prox control prox adc prox led current driver ch0 pdatah(r0x019) pdrive(r0x0f, b7:6) prox data external ir led ptime(r0x02) pvalid(r0x13, b1) v dd pdl(r0x0d,b0) ppulse(r0x0e) pgain(r0x0f, b3:2) poffset(r0x1e) psat(r0x13, b6) pdiode(r0x0f, b5:4) background energy pdatal(r0x018) ldr object figure 11. proximity detection the led current driver, output on the ldr terminal, provides a regulated current sink that eliminates the need for an external current limiting resistor. the combination of proximity led drive strength (pdrive) and proximity drive level (pdl) determine the drive current. pdrive sets the drive current to 120 ma, 60 ma, 30 ma, or 15 ma when pdl is not asserted. however, when pdl is asserted, the drive current is reduced by a factor of about 8 at v ldr = 1.6 v. to drive an external light source with more than 120 ma or to minimize on-chip ground bounce, ldr can be used to drive an external p-type transistor, which in turn drives the light source. referring to the detailed state machine figure, the led current driver pulses the external ir led as shown in figure 12 during the prox accum state. figure 12 also illustrates that the led on pulse has a fixed width of 7.3 s and period of 16.0 s. so, in addition to setting the proximity drive current, 1 to 255 proximity pulses (ppulse) can be programmed. when deciding on the number of proximity pulses, keep in mind that the signal increases proportionally to ppulse, while noise increases by the square root of ppulse. led on led off ir led pulses background energy reflected ir led + background energy 16.0 s 7.3 s figure 12. proximity led current driver waveform ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 12 copyright 2011, taos inc. the lumenology company www.taosinc.com figure 11 illustrates light rays emitting from an external ir led, reflecting off an object, and being absorbed by the ch0 and ch1 photodiodes. the proximity diode selector (pdiode) determines which of the two photodiodes is used for a given proximity measurement. note that neither photodiode is selected when the device first powers up, so pdiode must be set for proximity detection to work. referring again to figure 12, the reflected ir led and the background energy is integrated during the led on time, then during the led off time, the integrated background energy is subtracted from the led on time energy, leaving the external ir led energy to accumulate from pulse to pulse. the proximity gain (pgain) determines the integration rate, which can be programmed to 1 , 2 , 4 , or 8 gain. at power up, pgain defaults to 1 gain, which is recommended for most applications. for reference, pgain equal to 8 is comparable to the tsl2771 1 gain setting. during led on time integration, the proximity saturation bit in the status register (0x13) will be set if the integrator saturates. this condition can occur if the proximity gain is set too high for the lighting conditions, such as in the presence of bright sunlight. once asserted, psat will remain set until a special function proximity interrupt clear command is received from the host (see command register). after the progra mmed number of proximity pulses have been generated, the proximity adc converts and scales the proximity measurement to a 16-bit value, then stores the result in two 8-bit proximity data (pdatax) registers. adc scaling is controlled by the proximity adc conversion time (ptime) which is programmable from 1 to 256 2.73-ms time units. however, depending on the a pplication, scaling the proximity data will equally scale any accumulated noise. therefore, in general, it is recommended to leave ptime at the default value of one 2.73-ms adc conversion time (0xff). in many practical proximity applications, a number of optical system and environmental conditions can produce an offset in the proximity measurement result. to counter these effects, a proximity offset (poffset) is provided which allows the proximity data to be shifted positive or negative. additional information on the use of the proximity offset feature is provided in available taos application notes. once the first proximity cycle has completed, the proximity valid (pvalid) bit in the status register will be set and remain set until the proximity detection function is disabled (pen). for additional information on using the proximity detection function behind glass and for optical system design guidance, please see available taos application notes. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 13 the lumenology company copyright 2011, taos inc. www.taosinc.com interrupts the interrupt feature simplifies and improves system efficiency by eliminating the need to poll the sensor for light intensity or proximity values outside of a user-defined range. while the interrupt function is always enabled and it?s status is available in the status register (0x13), the output of the interrupt state can be enabled using the proximity interrupt enable (pien) or als interrupt enable (aien) fields in the enable register (0x00). four 16-bit interrupt threshold registers allow the user to set limits below and above a desired light level and proximity range. an interrupt can be generated when the als ch0 data (c0data) falls outside of the desired light level range, as determined by the values in the als interrupt low threshold registers (ailtx) and als interrupt high threshold registers (aihtx). likewise, an out-of-range proximity interrupt can be generated when the proximity data (pdata) falls below the proximity interrupt low threshold (piltx) or exceeds the proximity interrupt high threshold (pihtx). it is important to note that the thresholds are evaluated in sequence, first the low threshold, then the high threshold. as a result, if the low threshold is set above the high threshold, the high threshold is ignored and only the low threshold is evaluated. to further control when an interrupt occurs, the device provides a persistence filter. the persistence filter allows the user to specify the number of consecutive out-of-range als or proximity occurrences before an interrupt is generated. the persistence filter register (0x0c) allows the user to set the als persistence filter (apers) and the proximity persistence filter (ppers) values. see the persistence filter register for details on the persistence filter values. once the persistence filter generates an interrupt, it will continue until a special function interrupt clear command is received (see command register). prox adc prox data ch0 adc ch0 data prox integration ch0 ch1 upper limit upper limit lower limit lower limit prox persistence pilth(r09), piltl(r08) aihth(r07), aihtl(r06) als persistence ailth(r05), ailtl(r04) pihth(r0x0b), pihtl(r0x0a) ppers(r0x0c, b7:4) apers(r0x0c, b3:0) figure 13. programmable interrupt ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 14 copyright 2011, taos inc. the lumenology company www.taosinc.com system state machine timing the system state machine shown in figure 9 provides an overview of the states and state transitions that provide system control of the device. this section highlights the programmable features, which affect the state machine cycle time, and provides details to determine system level timing. when the proximity detection feature is enabled (pen), the state machine transitions through the prox init, prox accum, prox wait, and prox adc states. the prox init and prox wait times are a fixed 2.73 ms, whereas the prox accum time is determined by the number of proximity led pulses (ppulse) and the prox adc time is determined by the integration time (ptim e). the formulas to determine the prox accum and prox adc times are given in the associated boxes in figure 12. if an interrupt is generated as a result of the proximity cycle, it will be asserted at the end of the prox adc state and transition to the sleep state if sai is enabled. when the power management feature is enabled (wen), the state machine will transition in turn to the wait state. the wait time is determined by wlong, which extends normal operation by 12 when asserted, and wtime. the formula to determine the wait time is given in the box associated with the wait state in figure 14. when the als feature is enabled (aen), the state machine will transition through the als init and als adc states. the als init state takes 2.73 ms, while the als adc time is dependent on the integration time (a time). the formula to determine als adc time is given in the associated box in figure 14. if an interrupt is generated as a result of the als cycle, it will be asserted at the end of the als adc state and transition to the sleep state if sai is enabled. prox wait sleep idle wait prox init prox accum als adc als init als prox adc prox time: 2.73 ms ppulse: 0 ~ 255 pulses time: 16.0 s/pulse range: 0 ~ 4.1 ms time: 2.73 ms ptime: 1 ~ 256 steps time: 2.73 ms/step range: 2.73 ms ~ 699 ms wtime: 1 ~ 256 steps wlong = 0 wlong = 1 time: 2.73 ms/step 32.8 ms/step range: 2.73 ms ~ 699 ms 32.8 ms ~ 8.39s time: 2.73 ms atime: 1 ~ 256 steps time: 2.73 ms/step range: 2.73 ms ~ 699 ms int & sai !wen & !aen aen !pon i 2 c start wen !aen !pen & wen & aen !wen & aen note: pon, pen, wen, aen, and sai are fields in the enable register (0x00). !pen & !wen & aen pen int & sai figure 14. detailed state diagram ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 15 the lumenology company copyright 2011, taos inc. www.taosinc.com power management power consumption can be managed with the wait state, because the wait state typically consumes only 90 a of i dd current. an example of the power management feature is given below. with the assumptions provided in the example, average i dd is estimated to be 182 a. table 1. power management system state machine state programmable parameter programmed value duration typical current prox init 2.73 ms 0.200 ma prox accum ppulse 0x04 0.064 ms prox accum ? led on 0.029 ms (note 1) 119 ma prox accum ? led off 0.035 ms (note 2) 0.200 ma prox wait 2.73 ms 0.200 ma prox adc ptime 0xff 2.73 ms 0.200 ma wait wtime 0xee 49 2 ms 0 090 ma wait wlong 0 49.2 ms 0.090 ma als init 2.73 ms 0.200 ma als adc atime 0xee 49.2 ms 0.200 ma notes: 2. prox accum ? led on time = 7.3 s per pulse 4 pulses = 29.3 s = 0.029 ms 3. prox accum ? led off time = 8.7 s per pulse 4 pulses = 34.7 s = 0.035 ms average i dd current = ((0.029 119) + (0.035 x 0.200) + (2.73 0.200) + (49.2 0.090) + (49.2 0.200) + (2.73 0.200 3)) / 109 182 a keeping with the same programmed values as the example, table 2 shows how the average i dd current is affected by the wait state time, which is determined by wen, wtime, and wlong. note that the worst-case current occurs when the wait state is not enabled. table 2. average i dd current wen wtime wlong wait state average i dd current 0 n/a n/a 0 ms 258 a 1 0xff 0 2.73 ms 251 a 1 0xee 0 49.2 ms 182 a 1 0x00 0 699 ms 103 a 1 0x00 1 8389 ms 91 a ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 16 copyright 2011, taos inc. the lumenology company www.taosinc.com i 2 c protocol interface and control are accomplished through an i 2 c serial compatible interface (standard or fast mode) to a set of registers that provide access to device control functions and output data. the devices support the 7-bit i 2 c addressing protocol. the i 2 c standard provides for three types of bus transaction: read, write, and a combined protocol (figure 15). during a write operation, the first byte written is a command byte followed by data. in a combined protocol, the first byte written is the command byte followed by reading a series of bytes. if a read command is issued, the register address from the previous command will be used for data access. likewise, if the msb of the command is not set, the device will write a series of bytes at the address stored in the last valid command with a register address. the command byte contains either control information or a 5-bit register address. the control commands can also be used to clear interrupts. the i 2 c bus protocol was developed by philips (now nxp). for a complete description of the i 2 c protocol, please review the nxp i 2 c design specificati on at http ://www.i2c?bus.org/references/. a acknowledge (0) n not acknowledged (1) p stop condition r read (1) s start condition sr repeated start condition w write (0) ... continuation of protocol master-to-slave slave-to-master w 7 data byte slave address s 1 aa a 8 11 1 8 command code 1 p 1 ... i 2 c write protocol i 2 c read protocol i 2 c read protocol ? combined format r 7 data slave address s 1 aa a 8 11 1 8 data 1 p 1 ... w 7 slave address slave address s 1 ar a 8 11 1 7 11 command code sr 1 a data a a 81 8 data 1 p 1 ... figure 15. i 2 c protocols ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 17 the lumenology company copyright 2011, taos inc. www.taosinc.com register set the device is controlled and monitored by data registers and a command register accessed through the serial interface. these registers provide for a variety of control functions and can be read to determine results of the adc conversions. the register set is summarized in table 3. table 3. register address address resister name r/w register function reset value ?? command w specifies register address 0x00 0x00 enable r/w enables states and interrupts 0x00 0x01 atime r/w als time 0xff 0x02 ptime r/w proximity time 0xff 0x03 wtime r/w wait time 0xff 0x04 ailtl r/w als interrupt low threshold low byte 0x00 0x05 ailth r/w als interrupt low threshold high byte 0x00 0x06 aihtl r/w als interrupt high threshold low byte 0x00 0x07 aihth r/w als interrupt high threshold high byte 0x00 0x08 piltl r/w proximity interrupt low threshold low byte 0x00 0x09 pilth r/w proximity interrupt low threshold high byte 0x00 0x0a pihtl r/w proximity interrupt high threshold low byte 0x00 0x0b pihth r/w proximity interrupt high threshold high byte 0x00 0x0c pers r/w interrupt persistence filters 0x00 0x0d config r/w configuration 0x00 0x0e ppulse r/w proximity pulse count 0x00 0x0f control r/w control register 0x00 0x12 id r device id id 0x13 status r device status 0x00 0x14 c0data r ch0 adc low data register 0x00 0x15 c0datah r ch0 adc high data register 0x00 0x16 c1data r ch1 adc low data register 0x00 0x17 c1datah r ch1 adc high data register 0x00 0x18 pdatal r proximity adc low data register 0x00 0x19 pdatah r proximity adc high data register 0x00 0x1e poffset r/w proximity offset register 0x00 the mechanics of accessing a specific register depends on the specific protocol used. see the section on i 2 c protocols on the previous pages. in general, the command register is written first to specify the specific control/status register for following read/write operations. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 18 copyright 2011, taos inc. the lumenology company www.taosinc.com command register the command registers specifies the address of the target register for future write and read operations. table 4. command register 6 754 add 2 310 command command type reset 0x00 field bits description command 7 select command register. must write as 1 when addressing command register. type 6:5 selects type of transaction to follow in subsequent data transfers: field value description 00 repeated byte protocol transaction 01 auto-increment protocol transaction 10 reserved ? do not use 11 special function ? see description below transaction type 00 will repeatedly read the same register with each data access. transaction type 01 will provide an auto-increment function to read successive register bytes. add 4:0 address field/special function field. depending on the transaction type, see above, this field either specifies a special function command or selects the specific control-status-register for following write and read transactions. the field values listed below apply only to special function commands: field value description 00000 normal ? no action 00101 proximity interrupt clear 00110 als interrupt clear 00111 proximity and als interrupt clear other reserved ? do not write als/proximity interrupt clear clears any pending als/proximity interrupt. this special function is self clearing. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 19 the lumenology company copyright 2011, taos inc. www.taosinc.com enable register (0x00) the enable register is used to power the device on/off, enable functions, and interrupts. table 5. enable register 6 754 pon 2 310 enable reserved resv aien reset 0x00 aen pien wen pen sai field bits description reserved 7 reserved. write as 0. sai 6 sleep after interrupt. when asserted, the device will power down at the end of a proximity or als cycle if an interrupt has been generated. pien 5 proximity interrupt mask. when asserted, permits proximity interrupts to be generated. aien 4 als interrupt mask. when asserted, permits als interrupts to be generated. wen 3 wait enable. this bit activates the wait feature. writing a 1 activates the wait timer. writing a 0 disables the wait timer. pen 2 proximity enable. this bit activates the proximity function. writing a 1 enables proximity. writing a 0 disables proximity. aen 1 als enable. this bit actives the two channel adc. writing a 1 activates the als. writing a 0 disables the als. pon 0 power on. this bit activates the internal oscillator to permit the timers and adc channels to operate. writing a 1 activates the oscillator. writing a 0 disables the oscillator. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 20 copyright 2011, taos inc. the lumenology company www.taosinc.com als time register (0x01) the als time register controls the internal integration time of the als channel adcs in 2.73 ms increments. upon power up, the als time register is set to 0xff. table 6. als integration time register field bits description atime 7:0 value integ_cycles time max count 0xff 1 2.73 ms 1024 0xf6 10 27.3 ms 10240 0xdb 37 101 ms 37888 0xc0 64 175 ms 65535 0x00 256 699 ms 65535 proximity time register (0x02) the proximity time register controls the integration time of the proximity adc in 2.73 ms increments. upon power up, the proximity time register is set to 0xff. it is recommended that this register be programmed to a value of 0xff (1 integration cycle). table 7. proximity integration time control register field bits description ptime 7:0 value integ_cycles time max count 0xff 1 2.73 ms 1023 wait time register (0x03) wait time is set 2.73 ms increments unless the wlong bit is asserted in which case the wait times are 12 longer. wtime is programmed as a 2?s complement number. upon power up, the wait time register is set to 0xff. table 8. wait time register field bits description wtime 7:0 register value wait time time (wlong = 0) time (wlong = 1) 0xff 1 2.73 ms 0.033 sec 0xb6 74 202 ms 2.4 sec 0x00 256 699 ms 8.4 sec note: the proximity wait time register should be configured before pen and/or aen is/are asserted. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 21 the lumenology company copyright 2011, taos inc. www.taosinc.com als interrupt threshold registers (0x04 ? 0x07) the als interrupt threshold registers provides the values to be used as the high and low trigger points for the comparison function for interrupt generation. if c0data crosses below the low threshold specified, or above the higher threshold, an interrupt is asserted on the interrupt pin. table 9. als interrupt threshold registers register address bits description ailtl 0x04 7:0 als low threshold lower byte ailth 0x05 7:0 als low threshold upper byte aihtl 0x06 7:0 als high threshold lower byte aihth 0x07 7:0 als high threshold upper byte proximity interrupt threshold registers (0x08 ? 0x0b) the proximity interrupt threshold registers provide the values to be used as the high and low trigger points for the comparison function for interrupt generation. if the value generated by proximity channel crosses below the lower threshold specified, or above the higher threshold, an interrupt is signaled to the host processor. table 10. proximity interrupt threshold register s register address bits description piltl 0x08 7:0 proximity low threshold lower byte pilth 0x09 7:0 proximity low threshold upper byte pihtl 0x0a 7:0 proximity high threshold lower byte pihth 0x0b 7:0 proximity high threshold upper byte ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 22 copyright 2011, taos inc. the lumenology company www.taosinc.com persistence filter register (0x0c) the persistence filter register controls the interrupt capabilities of the device. configurable filtering is provided to allow interrupts to be generated after every adc cycle or if the adc cycle has produced a result that is outside of the values specified by threshold register for some specified amount of time. separate filtering is provided for proximity and als functions. als interrupts are generated using c0data. table 11. persistence filter register 6 754 apers 2 310 pers ppers reset 0x00 field bits description ppers 7:4 proximity interrupt persistence filter. controls rate of proximity interrupt to the host processor. field value meaning interrupt persistence function 0000 ??? every proximity cycle generates an interrupt 0001 1 1 proximity value out of range 0010 2 2 consecutive proximity values out of range ... ... ... 1111 15 15 consecutive proximity values out of range apers 3:0 als interrupt persistence filter. controls rate of als interrupt to the host processor. field value meaning interrupt persistence function 0000 every every als cycle generates an interrupt 0001 1 1 value outside of threshold range 0010 2 2 consecutive values out of range 0011 3 3 consecutive values out of range 0100 5 5 consecutive values out of range 0101 10 10 consecutive values out of range 0110 15 15 consecutive values out of range 0111 20 20 consecutive values out of range 1000 25 25 consecutive values out of range 1001 30 30 consecutive values out of range 1010 35 35 consecutive values out of range 1011 40 40 consecutive values out of range 1100 45 45 consecutive values out of range 1101 50 50 consecutive values out of range 1110 55 55 consecutive values out of range 1111 60 60 consecutive values out of range ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 23 the lumenology company copyright 2011, taos inc. www.taosinc.com configuration register (0x0d) the configuration register sets the proximity led drive level, wait long time, and als gain level. table 12. configuration register 6 7542 310 config reserved wlong reset 0x00 pdl agl field bits description reserved 7:3 reserved. write as 0. agl 2 als gain level. when asserted, the 1 and 8 als gain (again) modes are scaled by 0.16. otherwise, again is scaled by 1. do not use with again greater than 8 . wlong 1 wait long. when asserted, the wait cycles are increased by a factor 12 from that programmed in the wtime register. pdl 0 proximity drive level. when asserted, the proximity ldr drive current is reduced by 9. proximity pulse count register (0x0e) the proximity pulse count register sets the number of proxim ity pulses that the ldr pin will generate during the prox accum state. table 13. proximity pulse count register 6 7542 310 ppulse ppulse reset 0x00 field bits description ppulse 7:0 proximity pulse count. specifies the number of proximity pulses to be generated. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 24 copyright 2011, taos inc. the lumenology company www.taosinc.com control register (0x0f) the control register provides eight bits of miscellaneous control to the analog block. these bits typically control functions such as gain settings and/or diode selection. table 14. control register 6 7542 310 control pdrive resv reset 0x00 pdiode pgain again field bits description pdrive 7:6 proximity led drive strength. field value led strength ? pdl = 0 led strength ? pdl = 1 00 120 ma 15 ma 01 60 ma 7.5 ma 10 30 ma 3.8 ma 11 15 ma 1.9 ma pdiode 5:4 proximity diode selector. field value diode selection 00 proximity uses neither diode 01 proximity uses the ch0 diode 10 proximity uses the ch1 diode 11 reserved ? do not write pgain 3:2 proximity gain. field value proximity gain value 00 1 gain 01 2 gain 10 4 gain 11 8 gain again 1:0 als gain. field value als gain value 00 1 gain 01 8 gain 10 16 gain 11 120 gain id register (0x12) the id register provides the value for the part number. the id register is a read-only register. table 15. id register 6 7542 310 id id reset id field bits description id 7:0 part number identification 0x30 = TSL27721 & TSL27725 id 7:0 part number identification 0x39 = TSL27723 & tsl2777 ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 25 the lumenology company copyright 2011, taos inc. www.taosinc.com status register (0x13) the status register provides the internal status of the device. this register is read only. table 16. status register 6 754 avalid 2 310 status reserved resv aint reset 0x00 reserved pint pvalid psat field bit description reserved 7 reserved. bit reads as 0. psat 6 proximity saturation. indicates that the proximity measurement saturated. pint 5 proximity interrupt. indicates that the device is asserting a proximity interrupt. aint 4 als interrupt. indicates that the device is asserting an als interrupt. reserved 3:2 reserved. bits read as 0. pvalid 1 proximity valid. indicates that the proximity channel has completed an integration cycle after pen has been asserted. avalid 0 als valid. indicates that the als channels have completed an integration cycle after aen has been asserted. adc channel data registers (0x14 ? 0x17) als data is stored as two 16-bit values. to ensure the data is read correctly, a two-byte read i 2 c transaction should be used with auto increment protocol bits set in the command register. with this operation, when the lower byte register is read, the upper eight bits are stored in a shadow register, which is read by a subsequent read to the upper byte. the upper register will read the correct value even if additional adc integration cycles end between the reading of the lower and upper registers. table 17. adc channel data registers register address bits description c0data 0x14 7:0 als ch0 data low byte c0datah 0x15 7:0 als ch0 data high byte c1data 0x16 7:0 als ch1 data low byte c1datah 0x17 7:0 als ch1 data high byte proximity data registers (0x18 ? 0x19) proximity data is stored as a 16-bit value. to ensure t he data is read correctly, a two-byte read i 2 c transaction should be utilized with auto increment protocol bits set in the command register. with this operation, when the lower byte register is read, the upper eight bits are stored into a shadow register, which is read by a subsequent read to the upper byte. the upper register will read the correct value even if the next adc cycle ends between the reading of the lower and upper registers. table 18. proximity data register s register address bits description pdatal 0x18 7:0 proximity data low byte pdatah 0x19 7:0 proximity data high byte ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 26 copyright 2011, taos inc. the lumenology company www.taosinc.com proximity offset register (0x1e) the 8-bit proximity offset register provides compensation for proximity offsets caused by device variations, optical crosstalk, and other environmental factors. proximity offset is a sign-magnitude value where the sign bit, bit 7, determines if the offset is negative (bit 7 = 0) or positive (bit 7 = 1). at power up, the register is set to 0x00. the magnitude of the offset compensation depends on the proximity gain (pgain), proximity led drive strength (pdrive), and the number of proximity pulses (ppulse). because a number of environmental factors contribute to proximity offset, this register is best suited for use in an adaptive closed-loop control system. see available taos application notes fo r proximity offset register application information. table 19. proximity offset register 6 7542 310 poffset reset 0x00 magnitude sign field bit description sign 7 proximity offset sign. the offset sign shifts the proximity data negative when equal to 0 and positive when equal to 1. magnitude 6:0 proximity offset magnitude. the offset magnitude shifts the proximity data positive or negative, depending on the proximity offset sign. the actual amount of the shift depends on the proximity gain (pgain), proximity led drive strength (pdrive), and the number of proximity pulses (ppulse). ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 27 the lumenology company copyright 2011, taos inc. www.taosinc.com application information: hardware led driver pin with proximity detection in a proximity sensing system, the ir led can be pulsed by the TSL2772 with more than 100 ma of rapidly switching current, therefore, a few design considerations must be kept in mind to get the best performance. the key goal is to reduce the power supply noise coupled back into the device during the led pulses. the first recommendation is to use two power supplies; one for the device v dd and the other for the ir led. in many systems, there is a quiet analog supply and a noisy digital supply. by connecting the quiet supply to the v dd pin and the noisy supply to the led, the key goal can be meet. place a 1- f low-esr decoupling capacitor as close as possible to the v dd pin and another at the led anode, and a 22-f capacitor at the output of the led voltage regulator to supply the 100-ma current surge. TSL2772 int sda scl v dd ldr 1 f voltage regulator voltage regulator 22 f * cap value per regulator manufacturer recommendation ir led gnd v bus r p r p r pi c* 1 f figure 16. proximity sensing using separate power supplies if it is not possible to provide two separate power supplies, the device can be operated from a single supply. a 22- resistor in series with the v dd supply line and a 1- f low esr capacitor effe ctively filter any power supply noise. the previous capacitor placement considerations apply. TSL2772 int sda scl v dd ldr 1 f voltage regulator 22 f ir led gnd v bus r p r p r pi 1 f 22 figure 17. proximity sensing using single power supply v bus in the above figures refers to the i 2 c bus voltage which is either v dd or 1.8 v. be sure to apply the specified i 2 c bus voltage shown in the available options table for the specific device being used. the i 2 c signals and the interrupt are open-drain outputs and require pull?up resistors. the pull-up resistor (r p ) value is a function of the i 2 c bus speed, the i 2 c bus voltage, and the capacitive load. the taos evm running at 400 kbps, uses 1.5-k resistors. a 10-k pull-up resistor (r pi ) can be used for the interrupt line. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 28 copyright 2011, taos inc. the lumenology company www.taosinc.com application information: hardware pcb pad layouts suggested land pattern based on the ipc?7351b generic requirements for surface mount design and land pattern standard (2010) for the small outline no-lead (son) package is shown in figure 18. 0.35 6 2.70 1.20 0.65 0.65 1.20 top view notes: a. all linear dimensions are in millimeters. b. this drawing is subject to change without notice. figure 18. suggested fn package pcb layout ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 29 the lumenology company copyright 2011, taos inc. www.taosinc.com package information package fn dual flat no-lead 203 8 6 sda 5 int 4 ldr v dd 1 scl 2 gnd 3 top view side view bottom view lead free pb 300 50 650 bsc 2000 100 2000 100 pin 1 pin 1 end view 650 50 pin out top view 750 150 photodiode array area 295 nominal 355 10 398 10 c l of solder contacts c l of photodiode array area (note b) 1 nominal c l of solder contacts of photodiode array area (note b) c l 144 nominal notes: a. all linear dimensions are in micrometers. b. the die is centered within the package within a tolerance of 75 m. c. package top surface is molded with an electrically nonconductive clear plastic compound having an index of refraction of 1.55 . d. contact finish is copper alloy a194 with pre-plated nipdau lead finish. e. this package contains no lead (pb). f. this drawing is subject to change without notice. figure 19. package fn ? dual flat no-lead packaging configuration ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 30 copyright 2011, taos inc. the lumenology company www.taosinc.com carrier tape and reel information top view detail a 2.18 0.05 a o 0.254 0.02 5 max 4.00 8.00 3.50 0.05 1.50 4.00 2.00 0.05 + 0.30 ? 0.10 1.75 b b aa 1.00 0.25 detail b 2.18 0.05 b o 5 max 0.83 0.05 k o notes: a. all linear dimensions are in millimeters. dimension tolerance is 0.10 mm unless otherwise noted. b. the dimensions on this drawing are for illustrative purposes only. dimensions of an actual carrier may vary slightly. c. symbols on drawing a o , b o , and k o are defined in ansi eia standard 481?b 2001. d. each reel is 178 millimeters in diameter and contains 3500 parts. e. taos packaging tape and reel conform to the requirements of eia standard 481?b. f. in accordance with eia standard, device pin 1 is located next to the sprocket holes in the tape. g. this drawing is subject to change without notice. figure 20. package fn carrier tape ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 31 the lumenology company copyright 2011, taos inc. www.taosinc.com soldering information the fn package has been tested and has demonstrated an ability to be reflow soldered to a pcb substrate. the solder reflow profile describes the expected maximum heat exposure of components during the solder reflow process of pr oduct on a pcb. temperature is measured on top of component. the components should be limited to a maximum of three passes through this solder reflow profile. table 20. solder reflow profile parameter reference device average temperature gradient in preheating 2.5 c/sec soak time t soak 2 to 3 minutes time above 217 c (t1) t 1 max 60 sec time above 230 c (t2) t 2 max 50 sec time above t peak ?10 c (t3) t 3 max 10 sec peak temperature in reflow t peak 260 c temperature gradient in cooling max ?5 c/sec t 3 t 2 t 1 t soak t 3 t 2 t 1 t peak not to scale ? for reference only time (sec) temperature ( c) figure 21. solder reflow profile graph ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 32 copyright 2011, taos inc. the lumenology company www.taosinc.com storage information moisture sensitivity optical characteristics of the device can be adversely affected during the soldering process by the release and vaporization of moisture that has been previously absorbed into the package. to ensure the package contains the smallest amount of absorbed moisture possible, each device is baked prior to being dry packed for shipping. devices are dry packed in a sealed aluminized envelope called a moisture-barrier bag with silica gel to protect them from ambient moisture during shipping, handling, and storage before use. shelf life the calculated shelf life of the device in an unopened moisture barrier bag is 12 months from the date code on the bag when stored under the following conditions: shelf life: 12 months ambient t emperature: < 40 c relative humidity: < 90% rebaking of the devices will be required if the devices exceed the 12 month shelf life or the humidity indicator card shows that the devices were exposed to conditions beyond the allowable moisture region. floor life the fn package has been assigned a moisture sensitivity level of msl 3. as a result, the floor life of devices removed from the moisture barrier bag is 168 hours from the time the bag was opened, provided that the devices are stored under the following conditions: floor life: 168 hours ambient t emperature: < 30 c relative humidity: < 60% if the floor life or the temperature/humidity conditions have been exceeded, the devices must be rebaked prior to solder reflow or dry packing. rebaking instructions when the shelf life or floor life limits have been exceeded, rebake at 50 c for 12 hours. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 33 the lumenology company copyright 2011, taos inc. www.taosinc.com production data ? information in this document is current at publication date. products conform to specifications in accordance with the terms of texas advanced optoelectronic solutions, inc. standard warranty. production processing does not necessarily include testing of all parameters. lead-free (pb-free) and green statement pb-free (rohs) taos? terms lead-free or pb-free mean semiconductor products that are compatible with the current rohs requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. where designed to be soldered at high temperatures, taos pb-free products are suitable for use in specified lead-free processes. green (rohs & no sb/br) taos defines green to mean pb-free (rohs compatible), and free of bromine (br) and antimony (sb) based flame retardants (br or sb do not exceed 0.1% by weight in homogeneous material). important information and disclaimer the information provided in this statement represents taos? knowledge and belief as of the date that it is provided. taos bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. efforts are underway to better integrate information from third parties. taos has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. taos and taos suppliers consider certain information to be proprietary, and thus cas numbers and other limited information may not be available for release. notice texas advanced optoelectronic solutions, inc. (t aos) reserves the right to make changes to the products contained in this document to improve performance or for any other purpose, or to discontinue them without notice. customers are advised to contact taos to obtain the latest product information before placing orders or designing taos products into systems. taos assumes no responsibility for the use of any products or circuits described in this document or customer product design, conveys no license, either expressed or implied, under any patent or other right, and makes no representation that the circuits are free of patent infringement. taos further makes no claim as to the suitability of its products for any particu lar purpose, nor does taos assume any liability arising out of the use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. texas advanced optoelectronic solutions, inc. products are not designed or intended for use in critical applications in which the failure or malfunction of the taos product may result in personal injury or death. use of t aos products in life support systems is expressly unauthorized and any such use by a customer is completely at the customer?s risk. lumenology, taos, the taos logo, and texas advanced optoelectronic solutions are registered trademarks of texas advanced optoelectronic solutions incorporated. ams ag technical content still valid
TSL2772 light-to-digital converter with proximity sensing taos131 ? december 2011 34 copyright 2011, taos inc. the lumenology company www.taosinc.com ams ag technical content still valid

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