? semiconductor components industries, llc, 2004 may, 2004 ? rev. 8 1 publication order number: cs4122/d cs4122 triple air-core gauge driver with serial input bus the cs4122 converts digital data from a microprocessor to complementary dc outputs and drives air?core meter movements for vehicle instrument panels. it is optimized for one 360 gauge and two 112 gauges. the digital data controls the voltage applied to the quadrature coils of the meters with a 0.35 resolution for the major (360 ) gauge and 0.44 resolution for the minor (112 ) gauges. the accuracy is 0.75 for the major and 1.00 for the minors. the interface from the microcontroller is by a spi compatible serial connection using up to a 2.0 mhz shift clock rate. the digital code is shifted into the appropriate dac and multiplexer. these two blocks provide a tangential conversion function to change the digital data into the appropriate dc coil voltage. the major gauge driver can position a pointer anywhere within a 360 circle while the minor gauge drivers are limited to an arc of 112.2 . the output buffers are capable of 70 ma per coil and are protected against output short circuit conditions. a thermal protection circuit limits the junction temperature to approximately 160 c. an open?drain fault output goes low when any of the outputs are shorted or the device is in a thermal shutdown state. this asic is designed on powersense ? 3.0. features ? serial input bus ? 2.0 mhz operating frequency ? independently addressable gauges ? tangential drive algorithm ? 70 ma drive circuits ? 0.75 major accuracy ? power?on?reset ? protection features ? short circuit ? overtemperature ? internally fused leads in so?24l package so?24l dwf suffix case 751e 1 24 a = assembly location wl, l = wafer lot yy, y = year ww, w = work week marking diagram 1 cs4122 awlyyww 24 pin connections gnd gnd gnd gnd gnd gnd gnd gnd cos? sin+ cos+ sin? si cs so sclk c2? v bb /2 c2+ c1+ 124 fault v cc v bb c1? device package shipping 2 ordering information cs4122xdwf24 so?24l 31 units/rail cs4122xdwfr24 so?24l 1000 tape & reel 2for information on tape and reel specifications, including part orientation and tape sizes, please refer to our t ape and reel packaging specifications brochure, brd8011/d. http://onsemi.com
cs4122 http://onsemi.com 2 si serial to parallel shift register (12 bits) sclk so cs fault address decode + diag fault latch data decode/ latch data decode/ latch data decode/ latch por v cc v bb 7 bit dac 7 bit dac 7 bit dac mux mux mux por over temperature 2 8 8 10 7 7 7 d7 d7 d7 d8 ? d9 v top v var v bot v top v var v top v var oe oc output amplifiers sin+ 1/2 v bb sin? cos+ cos? c1+ c1? v bb /2 c2+ c2? gnd figure 1. block diagram maximum ratings (voltages are with respect to device substrate) rating value unit supply voltage v bb v cc ?1.0 to 16.5 ?1.0 to 6.0 v v digital inputs ?1.0 to 6.0 v steady state output current 100 ma forced injection current (inputs and supply) 10 ma operating junction temperature (t j ) 150 c storage temperature range (t stg ) ?65 to 150 c ja (thermal resistance junction?to?ambient) 55 c/w jc (thermal resistance junction?to?case) 9 c/w soldering temperature: reflow: (smd styles only) (note 1) 230 peak c maximum ratings are those values beyond which device damage can occur. maximum ratings applied to the device are individual str ess limit values (not normal operating conditions) and are not valid simultaneously. if these limits are exceeded, device functional operation i s not implied, damage may occur and reliability may be affected. 1. 60 second maximum above 183 c.
cs4122 http://onsemi.com 3 electrical characteristics (?40 c t a 105 c, 7.5 v v bb 14 v, 4.5 v v cc 5.5 v; unless otherwise specified.) characteristic test conditions min typ max unit supply voltages and currents analog supply current v bb = 14 v, no coil loads, r cos , r sin = 150 major @ 45 (code = 080 16 ), both minors @ 0 (codes = 00 16 ) major @ 0 (code = 000 16 ), both minors @ 56 (codes = 80 16 ) ? ? ? 5.20 310 81 25 340 100 ma ma ma logic supply current v cc = 5.5 v sclk = 2.0 mhz sclk = 0 mhz, v bb = 0 v ? ? 1.0 0.9 2.0 1.5 ma ma protection and power?on reset thermal shutdown drive outputs off ? 160 ? c power?on reset v cc rising v cc falling ? 2.5 ? ? 4.5 ? v v digital inputs and outputs output high voltage so = i out(high) = 0.8 ma v cc ? 0.8 ? ? v output low voltage so = i out(low) = 1.5 ma fault , i out(low) = 2.8 ma ? ? ? ? 0.4 0.8 v v fault leakage current v fault = 5.0 v ? ? 25 a input high voltage cs, sclk, si 0.7 v cc ? ? v input low voltage cs, sclk, si ? ? 0.3 v cc v input high current cs, sclk, si, v in = 0.7 v cc ? ? 1.0 a input low current cs, sclk, si, v in = 0.3 v cc ? ? 1.0 a sclk frequency ? ? ? 2.0 mhz sclk high time ? 175 ? ? ns sclk low time ? 175 ? ? ns so rise time 0.75 v to v cc ? 1.2 v; c l = 90 pf ? ? 100 ns so fall time v cc ? 1.2 v to 0.75 v; c l = 90 pf ? ? 100 ns so delay time c l = 90 pf ? ? 150 ns si setup time ? 75 ? ? ns si hold time ? 75 ? ? ns cs setup time ? 0 ? ? ns cs hold time ? 75 ? ? ns analog outputs output function accuracy major accuracy minor accuracy ? ? ? ? 0.75 1.00 output shutdown current, source and sink v bb = max v bb = min 70 43 ? ? ? ? ma ma major coil drive output voltage ? ? 0.748 v bb ? v minor coil drive output voltage ? ? 0.744 v bb ? v v bb /2 i dr(v bb /2) = 50 ma (0.5 v bb ) ? 0.1 ? (0.5 v bb ) + 0.1 v minimum load resistance t a = 105 c t a = 25 c t a = ?40 c 229 171 150 ? ? ? ? ? ?
cs4122 http://onsemi.com 4 pin function description pin # pin symbol function 1 sclk serial clock for shifting in/out of data. rising edge shifts data on si into the shift register and the falling edge changes the data on so. 2 cs when high, allows data at si to be shifted into the internal shift register with the rising edge of sclk. the falling edge transfers the shift register contents into the dac and multiplexer to update the output buffers. the falling edge also re?enables the output drivers if they have been disabled by a fault. 3 sin? negative output for sine coil. 4 sin+ positive output for sine coil. 5, 6, 7, 8, 17, 18, 19, 20 gnd ground for v bb and v cc supplies; device substrate. in the power soic package they aid in removing internally generated heat from the package and as such should be soldered to as large a pcb area as possible. 9 v bb /2 1/2 v bb output for biasing the minor coils. 10 c1+ positive output for the #1 minor coil. 11 c1? negative output for the #1 minor coil. 12 v cc 5.0 v logic supply. the internal registers and latches are reset by a por generated by the rising edge of the voltage on this lead. 13 fault open?drain fault flag. a logic low on this lead indicates that an output is shorted or the device is in thermal shutdown. 14 v bb analog supply. nominally 12 v. 15 c2+ positive output for the #2 minor coil. 16 c2? negative output for the #2 minor coil. 21 cos? negative output for cosine coil. 22 cos+ positive output for cosine coil. 23 si serial data input. data present at the rising edge of the clock signal is shifted into the internal shift register. 24 so serial data output. existing 12 bit data is shifted out when new data is shifted in. allows cascading of multiple devices on common serial port.
cs4122 http://onsemi.com 5 applications information theory of operation the cs4122 is for interfacing between a microcontroller or microprocessor and air?core meters commonly used in automotive vehicles for speedometers, tachometers and auxiliary gauges. these meters are built using 2 coils placed at 90 orientation to each other. a magnetized disc floats in the middle of the coils and responds to the magnetic field generated by each coil. the disc has a shaft attached to it that protrudes out of the assembly. a pointer indicator is attached to this shaft and in conjunction with a separate printed scale displays the vehicle's speed, engine's speed or other information such as fuel quantity or battery voltage. the disc (and pointer) respond to the vector sum of the voltages applied to the coils. ideally, this relationship follows a sine/cosine equation. since this is a transcendental and non?linear function, devices of this type use an approximation for this relationship. the cs4122 uses a tangential algorithm as shown in figure 2 for the major (360 ) gauge. only one output varies in any 45 range. note: the actual slopes are segmented but are shown here as straight lines for simplicity. sin+ output max(128) sin? output cos+ output cos? output max(128) max(128) max(128) min(0) min(0) min(0) min(0) 0 45 90 135 180 225 270 315 360 000 001 010 011 100 101 110 111 000 mux bits (d9?d7) degrees of rotation figure 2. major gauge outputs quadrant i tan ?1 (v sin ) (v sin ) (v cos ) (v cos ) for 0.176 to 44.824 : v sin tan 0.748 v bb v cos 0.748 v bb for 45.176 to 89.824 : v sin 0.748 v bb v cos tan(90 ) 0.748 v bb quadrant ii 180 tan ?1 (v sin ) (v sin ) (v cos ) (v cos ) for 90.176 to 134.824 : v sin 0.748 v bb v cos tan ( 90 ) 0.748 v bb for 135.176 to 179.824 : v sin tan(180 ) 0.748 v bb v cos 0.748 v bb quadrant iii 180 tan ?1 (v sin ) (v sin ) (v cos ) (v cos ) for 180.176 to 224.824 : v sin tan ( 180 ) 0.748 v bb v cos 0.748 v bb for 225.176 to 269.824 : v sin 0.748 v bb v cos tan (270 ) 0.748 v bb
cs4122 http://onsemi.com 6 quadrant iv 360 tan ?1 (v sin ) (v sin ) (v cos ) (v cos ) for 270.176 to 314.824 : v sin 0.748 v bb v cos tan( 270 ) 0.748 v bb for 315.176 359.824 : v sin tan (360 ) 0.748 v bb v cos 0.748 v bb 270 v sin? v sin+ 90 v cos? v cos+ 180 360/0 0.748 v bb 0.748 v bb 0.748 v bb 0.748 v bb iv iii ii i figure 3. major gauge response the minor gauge coil outputs differ in that only one of the coils in each movement is driven by the ic. the other is driven directly by the analog supply voltage, specifically one?half of this voltage. the common output assures that this is true. by varying the voltage across the other coil to a greater voltage, the pointer can be deflected more than 45 to each side of the externally driven coil. this relationship is shown in figure 4. note: there are actually eight segments, but only the are shown here for simplicity. 0 14 28 42 56 70 84 98 112 degrees of rotation c+ output max(128) c? output max(128) min(0) min(0) 00 1f 3f 5f 7f 9f bf df ff code 16 figure 4. minor gauge outputs quadrant i, ii 56.1 tan ?1 (v c ) (v c ) v bb v (v bb 2) v coil v (v bb 2) tan (56.1 ) figure 5. minor gauge outputs v c? v c+ 0.744 v bb 0.744 v bb 0 (?56.1) 112.2 56.1 v bb /2 iii to drive a gauge's pointer to a particular angle, the microcontroller sends a 12 bit digital word to the cs4122. these 12 bits are divided as shown in figure 6. however, from a software programmer's viewpoint, a 360 circle is divided into 1024 equal parts of 0.35 each and a 112.2 arc is divided into 256 parts of 0.44 each. table 1 shows the data associated with the 45 divisions of the 360 driver. table 2 shows the data for the center and end points of the 112.2 drivers. setting the address to a11o disables all outputs. gauge address = a00o d9 ? d7 select which octant divides a 45 octant into 128 equal parts to achieve a 0.35 resolution code 0 ? 127 10 major gauge (360 ) msb lsb d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 d10 d11 gauge address = a01o set to a00o deflection angle 0 ? 112.2 , to achieve a 0.44 resolution code 0 ? 255 10 minor gauge #1 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 d10 d11 gauge address = a10o set to a00o deflection angle 0 ? 112.2 , to achieve a 0.44 resolution code 0 ? 255 10 minor gauge #2 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 d10 d11 gauge address = a11o all outputs disabled; d9 ? d0 = adon't careo all gauges disabled d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 d10 d11 figure 6. definition of serial word
cs4122 http://onsemi.com 7 table 1. nominal output for major gauge (v bb = 14 v) input code (decimal) ideal degrees nominal degrees v sin (v) v cos (v) 0 0 0.176 0.032 10.472 128 45 45.176 10.472 10.412 256 90 90.176 10.472 ?0.032 384 135 135.176 10.412 ?10.472 512 180 180.176 ?0.032 ?10.472 640 225 225.176 ?10.472 ?10.412 768 270 270.176 ?10.472 0.032 896 315 315.176 ?10.476 10.412 1023 359.65 359.826 ?0.032 10.472 table 2. nominal output for minor gauges (v bb = 14 v) input code (decimal) scale degrees degrees from center v coil 0 0 ?56.1 10.417 127 55.88 ?0.22 0.027 128 56.32 0.22 ?0.027 255 112.2 56.1 ?10.417 the 12 bits are shifted into the device's shift register msb first using a spi compatible scheme. this method is shown in figures 6 and 7. the first 2 bits select the output driver for which the data is intended. the cs must be high and remain high for sclk to be enabled. data on si is shifted in on the rising edge of the synchronous clock signal. data in the shift register is shifted to so on the falling edge of sclk. this arrangement allows the cascading of devices. so is always enabled. data shifts through without affecting the outputs until cs is brought low. at this time, the internal dac is updated and the outputs change accordingly. cs si sclk so si (setup) si (hold) so (tpd) so (rise, fall) 10% ? 90% cs hold cs setup figure 7. serial data timing diagram the dac for the major gauge driver outputs 128 discrete levels selected by bits d6 ? d0. these bits are xor'd with d7 to invert them when choosing the 2nd half of each quadrant (each odd octant). this reduces the number of resistors and switches required. the mux chooses which signals to send to the output amplifiers based upon d9 ? d7. there are three choices for each amplifier: high, low or the dac output. the dac's for the minor gauge drivers similarly output 128 discrete levels selected by bits d6 ? d0. these bits are also xor'd with d7 to invert them when choosing the 2nd half of the output range. the mux chooses which signals to send to the output amplifiers based upon d7. there are two choices for each amplifier; high or the dac output. bits d8 and d9 are not used, but should be set to a00o to ensure that the minor gauge outputs are enabled. the output buffers are unity gain amplifiers. each of the eight outputs are designed to swing close to the supply rails to maximize the voltage across the coils to produce maximum torque. additionally, this lowers the power dissipation. the current for each output is also monitored. if any of the major gauge outputs exceed the maximum value, all of the major outputs are disabled. if any of the minor gauge outputs exceed the maximum value, all of the minor outputs are disabled. the falling edge of the cs re?enables the outputs with the fault condition but they remain on only if the overcurrent situation has been eliminated.
cs4122 http://onsemi.com 8 application diagrams v bat figure 8. full application sin? c2+ c2? cos? c1? c1+ gnd cs si so sclk cos+ cs4122 sin+ spi irq host controller 360 112 112 ena voltage regulation* +12 v +5.0 v cs8156 20 k v ign v out1 v out2 v in v in fault v cc v bb 360 112 sin? c2+ c2? cos? c1? c1+ gnd cs si so sclk cos+ cs4122 sin+ fault v cc v bb figure 9. application with one minor gauge v bb /2 v bb /2 *on semiconductor offers a complete line of automotive voltage regulators. visit http://onsemi.com and search for the automotive analog products guide, sgd516/d. for additional information, please contact your local sales representative.
cs4122 http://onsemi.com 9 package dimensions so?24l dwf suffix case 751e?04 issue e notes: 1. dimensioning and tolerancing per ansi y14.5m, 1982. 2. controlling dimension: millimeter. 3. dimensions a and b do not include mold protrusion. 4. maximum mold protrusion 0.15 (0.006) per side. 5. dimension d does not include dambar protrusion. allowable dambar protrusion shall be 0.13 (0.005) total in excess of d dimension at maximum material condition. ?a? ?b? p 12x d 24x 12 13 24 1 m 0.010 (0.25) b m s a m 0.010 (0.25) b s t ?t? g 22x seating plane k c r x 45 m f j dim min max min max inches millimeters a 15.25 15.54 0.601 0.612 b 7.40 7.60 0.292 0.299 c 2.35 2.65 0.093 0.104 d 0.35 0.49 0.014 0.019 f 0.41 0.90 0.016 0.035 g 1.27 bsc 0.050 bsc j 0.23 0.32 0.009 0.013 k 0.13 0.29 0.005 0.011 m 0 8 0 8 p 10.05 10.55 0.395 0.415 r 0.25 0.75 0.010 0.029 package thermal data parameter so?24l unit r jc typical 9 c/w r ja typical 55 c/w
cs4122 http://onsemi.com 10 on semiconductor and are registered trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to mak e changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for an y particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including wi thout limitation special, consequential or incidental damages. atypicalo parameters which may be provided in scillc data sheets and/or specifications can and do vary in different application s and actual performance may vary over time. all operating parameters, including atypicalso must be validated for each customer application by customer's technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the scillc product could create a sit uation where personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its officers, employees, subsidiaries, af filiates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, direct ly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. this literature is subject to all applicable copyright laws and is not for resale in any manner. publication ordering information n. american technical support : 800?282?9855 toll free usa/canada japan : on semiconductor, japan customer focus center 2?9?1 kamimeguro, meguro?ku, tokyo, japan 153?0051 phone : 81?3?5773?3850 cs4122/d powersense is a trademark of semiconductor components industries, llc (scillc). literature fulfillment : literature distribution center for on semiconductor p.o. box 5163, denver, colorado 80217 usa phone : 303?675?2175 or 800?344?3860 toll free usa/canada fax : 303?675?2176 or 800?344?3867 toll free usa/canada email : orderlit@onsemi.com on semiconductor website : http://onsemi.com order literature : http://www.onsemi.com/litorder for additional information, please contact your local sales representative.
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