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features and benefits ? fully optimized differential digital gear tooth sensor ic ? running mode lockout ? unique algorithms for increased vibration immunity ? agc and reference adjust circuit ? air gap independent switchpoints ? digital output representing gear profile ? precise duty cycle throughout operating temperature range ? large operating air gap range ? short power-on time ? true zero-speed operation ? undervoltage lockout (uvlo) ? wide operating voltage range ? internal current regulator for two-wire operation ? single-chip sensing ic for high reliability ? robust test coverage capability using scan path and iddq measurement description the ATS685LSH is an optimized hall-effect sensing integrated circuit and rare-earth pellet combination that provides a user-friendly solution for true zero-speed digital gear-tooth sensing in two-wire applications. the sensor ic consists of a single-shot molded plastic package that includes a samarium cobalt pellet, a pole piece, and a hall effect ic that has been optimized to the magnetic circuit. this small package can be easily assembled and used in conjunction with a wide variety of gear shapes and sizes. the single integrated circuit incorporates a dual element hall-effect sensor ic and signal processing circuitry that switches in response to differential magnetic signals created by ferromagnetic targets. the device contains a sophisticated compensating circuit to eliminate magnetic and system offsets. digital tracking of the analog signal is used to achieve true zero speed operation. advanced calibration algorithms are used to adjust the device gain and offset at power-up, resulting in air gap independent switchpoints, which greatly improves output accuracy. in addition, advanced algorithms mitigate the effect of system anomalies such as target vibration and sudden changes in air gap. the regulated current output is configured for two-wire operation. this sensor ic is ideal for obtaining edge and duty cycle information in gear-tooth?based applications such as transmission speed. the ats685 is provided in a 4-pin sip package that is lead (pb) free, with 100% matte tin leadframe plating. ATS685LSH-ds two-wire, zero speed differential gear tooth sensor ic package: 4-pin sip (suffix sh) functional block diagram not to scale ATS685LSH gnd vcc test multiplexor voltage regulator hall amp offset adjust reference generator and lockout pdac agc synchronous digital controller ndac
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 2 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com pin-out diagram terminal list table number name function 1 vcc supply voltage 2 nc no connection (float or tie to gnd) 3 test test (float or tie to gnd) 4 gnd ground selection guide part number packing* ATS685LSHtn-t 13-in. reel, 800 pieces per reel *contact allegro ? for additional packing options absolute maximum ratings characteristic symbol notes rating units supply voltage v cc 26.5 v reverse supply voltage v rcc ?18 v operating ambient temperature t a range l, refer to power derating curve ?40 to 150 oc maximum junction temperature t j (max) 165 oc storage temperature t stg ?65 to 170 oc 24 3 1
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 3 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com operating characteristics v cc and t a within specification, unless otherwise noted characteristics symbol test conditions min. typ. 1 max. unit 2 electrical characteristics supply voltage 3 v cc operating, t j < t j (max), i cc within specification 4.0 ? 24 v undervoltage lockout v cc(uv) v cc 0 5 v or 5 0 v ? 3.5 3.95 v reverse supply current 4 i rcc v cc = ?18 v ? ? ?10 ma supply zener clamp voltage v z i cc = i cc (max) + 3 ma, t a = 25c 28 ? ? v supply zener current i z t a = 25c, v cc = 28 v ? ? 19 ma supply current i cc(low) low-current state 4 6 8 ma i cc(high) high-current state 12 14 16 ma supply current ratio i cc(high) / i cc(low) ratio of high current to low current 1.85 ? 3.05 ? test pin zener clamp voltage 5 v ztest ?6?v power-on state characteristics power-on time 6 t po v cc > v cc (min), f op < 100 hz ? 1 2 ms power-on state 7 pos t > t po ?i cc(high) ?a output stage output slew rate 8,9 di / dt i / t from 90% to 10% i cc level r sense = 100 , c load = 10 pf, no c bypass 7 14 ? ma/ s performance characteristics operating frequency f op 0 ? 12 khz analog signal bandwidth bw 16 20 ? khz operate point b op % of peak-to-peak b sig , ag op within specification ?70? % release point b rp % of peak-to-peak b sig , ag op within specification ?30? % running mode lockout enable threshold v loe(rm) at peak-to-peak v proc < v loe(rm) , output switching disables ? 170 ? mv running mode lockout release threshold v lor(rm) at peak-to-peak v proc > v lor(rm) , output switching enables ? 200 ? mv calibration start mode hysteresis po hys ?v lor(rm) ?mv initial calibration 10 cal i rising output (current) edges, f op < 200 hz ? ? 3 edges continued on the next page?
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 4 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com functional characteristics operating signal range 11 b sig differential magnetic signal, duty cycle within specification 50 ? 1500 g pk-pk extended operating signal range b sigext differential magnetic signal, output switching (no missed edges), duty cycle not guaranteed 30 ? ? g pk-pk operational air gap range ag op using allegro reference target 60-0, duty cycle within specification 0.5 ? 2.5 mm extended operational air gap range ag ext using allegro reference target 60-0, output switching (no missed edges), duty cycle not guaranteed ? ? 3.0 mm allowable user-induced differential offset b diffext operation within specification 60 ? ? g duty cycle variation 12 d wobble < 0.5 mm, ag within specification ? ? 10 % maximum sudden signal amplitude change b sig(inst) instantaneous symmetric magnetic signal amplitude change, measured as a percentage of peak-to-peak b sig , f op < 500 hz ?45? % 1 typical values are at t a = 25c and v cc = 12 v. performance may vary for individual units, within the specified maximum and minimum limits. 2 1 g (gauss) = 0.1 mt (millitesla). 3 maximum voltage must be adjusted for power dissipation and junction temperature; see power derating section. 4 negative current is defined as conventional current coming out of (sourced from) the specified device terminal. 5 sustained voltages beyond the clamp voltage may cause permanent damage to the ic. 6 measured from v cc v cc (min) to the time when the device is able to switch the output signal in response to a magnetic stimulus. 7 please refer to the functional description, power-on section. 8 di is the difference between 10% of i cc(low) and 90% of i cc(high) . dt is the time period between those two points. 9 c load is the probe capacitance of the oscilloscope used to make the measurement. 10 for power-on frequency, f op < 200 hz. higher power-on frequencies may result in more input magnetic cycles until full output edge accuracy is achieved, including the possibility of missed output edges. 11 ag op is dependent on the available magnetic field. the available field is dependent on target geometry and material, and should be independently characterized. the field available from the reference target is given in the reference target table. 12 target rotation from pin 4 to pin 1. operating characteristics (continued) v cc and t a within specification, unless otherwise noted characteristics symbol test conditions min. typ. 1 max. unit 2
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 5 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com reference gear magnetic profile reference target 60-0, hall element spacing 2.20 mm gear rotation () air gap (mm) differential b (g) 0 2 4 6 8 10 12 14 16 18 20 600 400 200 0 200 400 600 0.50 mm ag 3.00 mm ag 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 12 0 3 1200 1000 800 600 400 200 0 reference gear magnetic gradient amplitude versus air gap reference target 60-0, hall element spacing 2.20 mm air gap (mm) peak-to-peak differential b (g) reference target 60-0 (60 tooth target) characteristics symbol test conditions typ. units symbol key outside diameter d o outside diameter of target 120 mm t t v ? d o h t f branded face of package air gap face width f breadth of tooth, with respect to branded face 6mm angular tooth thickness t length of tooth, with respect to branded face 3 deg. angular valley thickness t v length of valley, with respect to branded face 3 deg. tooth whole depth h t 3mm material low carbon steel ? ? reference target 60-0 of package branded face
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 6 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com thermal characteristics may require derating at maximum conditions, see power derating section characteristic symbol test conditions* value unit package thermal resistance r ja single layer pcb, with copper limited to solder pads 126 oc/w single layer pcb, with copper limited to solder pads and 3.57 in. 2 (23.03 cm 2 ) copper area each side 84 oc/w *additional thermal information available on the allegro website 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 temperature (c) maximum allowable v cc (v) v cc (max) v cc (min) power derating curve at maximum supply current, i cc = i cc(high) (max) 20 40 60 80 100 120 140 160 180 (r ja = 84 c/w) (r ja = 126 c/w) 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 0 20 40 60 80 100 120 140 160 180 temperature,t a (c) power dissipation, p d (m w) r q ja = 126 oc/w r q ja = 84 oc/w power dissipation versus ambient temperature at maximum supply current, i cc = i cc(high) (max)
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 7 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com functional description sensing technology the ats685 sensor ic contains a single-chip differential hall- effect circuit, a samarium cobalt pellet, and a flat ferrous pole piece (a precisely-mounted magnetic field concentrator that homogenizes the flux passing through the hall chip). as shown in figure 1, the circuit supports two hall elements, which sense the magnetic profile of the ferromagnetic gear target simultaneously, but at different points (spaced at a 2.2 mm pitch), generating a differential internal analog voltage, v proc , that is processed for precise switching of the digital output signal. the hall ic is self-calibrating and also integrates a tempera- ture compensated amplifier and offset cancellation circuitry. its voltage regulator provides supply noise rejection throughout the operating voltage range. changes in temperature do not greatly affect this device due to the stable amplifier design and the offset rejection circuitry. the hall transducers and signal processing electronics are integrated on the same silicon substrate, using a proprietary bicmos process. target profiling during operation under normal operating conditions, the ic is capable of provid- ing digital information that is representative of the mechanical features of a rotating gear. the waveform diagram in figure 2 presents the automatic translation of the mechanical profile, through the magnetic profile that it induces, to the digital output signal of the ats685. no additional optimization is needed and minimal processing circuitry is required. this ease of use reduces design time and incremental assembly costs for most applications. diagnostics the regulated current output is configured for two-wire applica- tions, requiring one less wire for operation than do switches with the traditional open-collector output. additionally, the system designer inherently gains diagnostics because there is always output current flowing, which should be in either of two nar- row ranges, shown in figure 3 as i cc(high) and i cc(low) . any current level not within these ranges indicates a fault condition. if i cc > i cc(high) (max), then a short condition exists, and if i cc < i cc(low) (min), then an open condition exists. any value of i cc between the allowed ranges for i cc(high) and i cc(low) indicates a general fault condition. target (gear) back-biasing rare-earth pellet south pole north pole case (pin 1 side) (pin 4 side) hall ic pole piece element pitch (concentrator) dual-element hall effect device hall element 1 hall element 2 figure 1. relative motion of the target is detected by the dual hall elements mounted on the hall ic. figure 2. the magnetic profile reflects the geometry of the target, allowing the ats685 to present an accurate digital output response. b op(#1) b rp(#1) b op(#2) off on on off device internal switch state device package orientation to target device internal differential analog signal, v proc device output signal, i cc (pin 1 side) (pin 4 side) ic element pitch hall element 1 hall element 2 device branded face target magnetic profile +b +t +t mechanical position (target moves past sensor pin 1 to pin 4) target (gear) this tooth sensed earlier this tooth sensed later (view of side away from pins) i cc(high) (max) i cc(high) (min) i cc(low) (max) i cc(low) (min) range for valid i cc(high) range for valid i cc(low) 0 +ma ? ? short fault open figure 3. diagnostic characteristics of supply current values.
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 8 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com determining output signal polarity in figure 2, the top panel, labeled mechanical position , represents the mechanical features of the target gear and orientation to the device. the bottom panel, labeled device output signal , displays the square waveform corresponding to the digital output signal (current amplitude) that results from a rotating gear configured as shown in figure 3. referring to the target side nearest the face of the sensor ic, the direction of rotation is: perpendicular to the leads, across the face of the device, from the pin 1 side to the pin 4 side. in order to read the output signal as a voltage, v sense , a sense resistor, r sense , can be placed on either the vcc signal or on the gnd signal. as shown in figure 4, when r sense is placed on the gnd signal, the output signal voltage, v sense(lowside) , is in phase with i cc . when r sense is placed on the vcc signal, the output signal voltage, v sense(highside) , is inverted relative to i cc . rotating target brande of package pin 1 pin 4 dface figure 3. this figure depicts left-to-right (pin 1 to pin 4) direction of target rotation. figure 4. alternative polarity configurations using two-wire sensing. the output polarity states table provides the permutations of output voltage relative to i cc , given alternative locations for r sense . panel a shows the low-side, v sense(lowside) , sensing configuration, and panel b shows the high-side, v sense(highside) , configuration. as shown in panel c, v sense(lowside) is in phase with i cc , and v sense(highside) , is inverted. ats685 vcc gnd v cc 1 4 ats685 vcc gnd v cc 1 4 v sense(highside) v sense(lowside) r sense r sense i cc i cc output polarity states r sense location i cc state v sense state high side (vcc pin side) high low low high low side (gnd pin side) high high low low i cc v sense(highside) v+ v sense(lowside) v+ i+
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 9 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com (a) teag varying; cases such as eccentric mount, out-of-round region, normal operation position shift (b) internal analog signal, v proc , typically resulting in the ic 0 b op b rp b op b rp b op b rp b op b rp b op b op b rp 360 target rotation () hysteresis band (delimited by switchpoints) v proc (v) v+ (c) internal analog signal, v proc , representing magnetic field for digital output v proc (v) v out (v) v+ larger teag smaller teag ic target larger teag target ic smaller teag smaller teag figure 5. the continuous update algorithm allows the allegro ic to interpret and adapt to variances in the magnetic field gener ated by the target as a result of eccentric mounting of the target, out-of-round target shape, and similar dynamic application problems that affec t the teag (total effective air gap). as shown in panel a, the variance in the target position results in a change in the teag. this affects the ic as a varying magnetic field, which results in proportional changes in the internal analog signal, v proc , shown in panel b. the continuous update algorithm is used to establish switchpoints based on the fluctuation of v proc , as shown in panel c. continuous update of switchpoints switchpoints are the threshold levels of the differential internal analog signal, v proc , at which the device changes output signal state. the value of v proc is directly proportional to the magnetic flux density, b, induced by the target and sensed by the hall elements. as v proc rises through a certain limit, referred to as the operate point , b op , the output state changes from high to low. as v proc falls below b op to a certain limit, the release point , b rp , the output state changes from low to high. as shown in figure 5, threshold levels for the switchpoints are established as a function of the peak input signal levels. the device incorporates an algorithm that continuously monitors the input signal and updates the switching thresholds accordingly with limited inward movement of v proc . the switchpoint for each edge is determined by the detection of the previous two signal edges. in this manner, variations are tracked in real time.
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 10 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com power-on the ats685 is guaranteed to power-on in the high current state, i cc(high) . when power (v cc > v cc (min) ) is applied to the device, a short period of time is required to power the vari- ous portions of the circuit. during this period, the ats685 will power-on in the high current state, i cc(high) . initial edge detection the device self-calibrates using the initial teeth sensed, and then enters running mode. this results in reduced accuracy for a brief period, cal i . however, this period allows the device to optimize for running mode operation. as shown in figure 6, the first three high peak signals corresponding to rising output edges are used to calibrate agc (automatic gain control). there is a slight vari- ance in the duration of initialization, depending on what target feature is opposite the sensor ic when power-on occurs. also, a high speed of target rotation at power-on may increase the quan- tity required in the cal i period. figure 6. power-on initial edge detection. this figure demonstrates four typical power-on scenarios. all of these examples assu me that the target is moving relative to the sensor ic in the direction indicated (from pin 1 to pin 4) and the voltage output is configured for low- side sensing, v out(low) . the length of time required to overcome start mode hysteresis, as well as the combined effect of whether it is overcome in a positi ve or negative direction plus whether the next edge is in that same or opposite polarity, affect the point in time when agc calibration begins. three hi gh peaks are always required for agc calibration when f op 200 hz, and more may be required at greater speeds. target (gear) i cc v proc v proc v proc v proc v proc v proc v proc v proc i cc i cc i cc i cc i cc i cc i cc power-on opposite tooth power-on at falling mechanical edge power-on at rising mechanical edge power-on opposite valley agc calibration running mode agc calibration running mode agc calibration running mode agc calibration running mode device position 1 1 4 4 2 2 3 3 start mode hysteresis overcome start mode hysteresis overcome start mode hysteresis overcome start mode hysteresis overcome
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 11 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com start mode hysteresis this feature helps to ensure optimal self-calibration by rejecting electrical noise and low-amplitude target vibration during initial- ization. this prevents agc from calibrating the device on such spurious signals. calibration can be performed using the actual target features. a typical scenario is shown in figure 7. the hysteresis, po hys , is a minimum level of the peak-to-peak amplitude of the internal analog electrical signal, v proc , that must be exceeded before the ats685 starts to compute switchpoints. b op b rp b rp b rp(initial) b op(initial) 1 4 2 3 start mode output signal, i cc if exceed po hys on high side if exceed po hys on low side ic position relative to target target magnetic profile differential signal, v proc target, gear hysteresis, po hys figure 7. operation of start mode hysteresis ? at power-on (position 1), the ats685 begins sampling v proc . ? at the point where the start mode hysteresis, po hys , is exceeded, the device establishes an initial switching threshold, by using the continuous update algorithm. if v proc is rising through the limit on the high side (position 2), the switchpoint is b op , and if v proc is falling through the limit on the low side (position 4), it is b rp . after this point, start mode hysteresis is no longer a consideration. note that a valid v proc value exceeding the start mode hysteresis can be generated either by a legitimate target feature or by excessive vibration. ? in either case (b op or b rp ), because the switchpoint is immediately passed as soon as it is established, the ats685 en- ables switching: ? if on the high side, at b op (position 2) the output would switch from low to high. however, because output is already high, no output switching occurs. at the next switchpoint, where b rp is passed (position 3), the output switches from high to low. ? if on the low side, at b rp (position 4) the output switches from high to low.
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 12 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com undervoltage lockout when the supply voltage falls below the minimum operating voltage, v cc(uv) , i cc goes high and remains high regardless of the state of the magnetic gradient from the target. this lockout feature prevents false signals, caused by undervoltage conditions, from propagating to the output of the device. because v cc is below the v cc (min) specification during lockout, the i cc levels may not be within specification. power supply protection the device contains an on-chip regulator and can operate over a wide v cc range. for devices that need to operate from an unregu- lated power supply, transient protection must be added externally. for applications using a regulated line, emi/rfi protection may still be required. contact allegro for information on the circuitry needed for compliance with various emc specifications. refer to figure 8 for an example of a basic application circuit. automatic gain control (agc) this feature allows the device to operate with an optimal internal electrical signal, regardless of the air gap (within the ag specifica- tion). at power-on, the device determines the peak-to-peak ampli- tude of the signal generated by the target. the gain is then auto- matically adjusted. figure 9 illustrates the effect of this feature. running mode gain adjust the ats685 has a feature during running mode to compensate for dynamic air gap variation. if the system increases the mag- netic input drastically, the device will gradually readjust the gain downwards, allowing the chip to regain the optimum internal electrical signal with the new, larger, magnetic signal. dynamic offset cancellation (doc) the offset circuitry when combined with agc automatically reduces the effects of chip, magnet, and installation offsets. this circuitry is continuously active, including both power-on mode and running mode, compensating for any offset drift (within allowable user-induced differential offset). continuous opera- tion also allows it to compensate for offsets induced by tempera- ture variations over time. running mode lockout the ats685 has a running mode lockout feature to prevent switching on small signals that are characteristic of vibration signals. the internal logic of the chip evaluates small signal amplitudes below a certain level to be vibration. in that event, the output is blanked (locked-out) until the amplitude of the signal returns to normal operating levels. watchdog the ats685 employs a watchdog circuit to prevent extended loss of output switching during sudden impulses and vibration in the system. if the system changes the magnetic input drastically such that target feature detection is terminated, the device will fully reset itself, allowing the chip to recalibrate properly on the new magnetic input signal. mechanical profile ag small ag large ag small ag large internal differential analog signal response, with agc internal differential analog signal response, without agc ferrous target v+ v+ figure 9. automatic gain control (agc). the agc function corrects for variances in the air gap. differences in the air gap cause differences in the magnetic field at the device, but agc prevents that from affecting device performance, as shown in the lowest panel. figure 8. typical circuit for proper device operation. 2 ats685 1 3 4 0.01 m f (optional) 100 7 r sense c load c bypass v cc
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 13 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com power derating the device must be operated below the maximum junction temperature of the device, t j(max) . under certain combinations of peak conditions, reliable operation may require derating supplied power or improving the heat dissipation properties of the appli- cation. this section presents a procedure for correlating factors affecting operating t j . (thermal data is also available on the allegro website.) the package thermal resistance, r ? ja , is a figure of merit sum- marizing the ability of the application and the device to dissipate heat from the junction (die), through all paths to the ambient air. its primary component is the effective thermal conductivity, k, of the printed circuit board, including adjacent devices and traces. radiation from the die through the device case, r ? jc , is relatively small component of r ? ja . ambient air temperature, t a , and air motion are significant external factors, damped by overmolding. the effect of varying power levels (power dissipation, p d ), can be estimated. the following formulas represent the fundamental relationships used to estimate t j , at p d . p d = v in i in (1) ?? ? t = p d r ? ja (2) t j = t a + t (3) for example, given common conditions such as: t a = 25c, v cc = 12 v, i cc = 6 ma, and r ? ja = 126 c/w, then: p d = v cc i cc = 12 v 6 ma = 72 mw ?? t = p d r ? ja = 72 mw 126 c/w = 9.1c t j = t a + ? t = 25c + 9.1c = 34.1c a worst-case estimate, p d (max), represents the maximum allow- able power level (v cc (max), i cc (max)), without exceeding t j (max), at a selected r ? ja and t a . example : reliability for v cc at t a = 150c, package sh, using a single-layer pcb. observe the worst-case ratings for the device, specifically: r ? ja = 126 c/w, t j (max) = 165c, v cc (max) = 28 v, and i cc (max) = 16 ma. calculate the maximum allowable power level, p d (max). first, invert equation 3: ? t max = t j (max) ? t a = 165 c ? 150 c = 15 c this provides the allowable increase to t j resulting from internal power dissipation. then, invert equation 2: ???? p d (max) = ? t max r ? ja = 15c 126 c/w = 119 mw finally, invert equation 1 with respect to voltage: v cc (est) = p d (max) i cc (max) = 119 mw 16 ma = 7.4 v the result indicates that, at t a , the application and device can dissipate adequate amounts of heat at voltages v cc (est). compare v cc (est) to v cc (max). if v cc (est) v cc (max), then reliable operation between v cc (est) and v cc (max) requires enhanced r ? ja . if v cc (est) v cc (max), then operation between v cc (est) and v cc (max) is reliable under these conditions.
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 14 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com package sh, 4-pin sip 0.710.05 5.000.10 4.000.10 1.000.10 0.600.10 24.650.10 13.100.10 1.0 ref 0.71 0.10 0.71 0.10 1.60 0.10 1.270.10 5.50 0.10 5.500.05 8.000.05 5.800.05 1.700.10 24 3 1 a a b d for reference only, not for tooling use (reference dwg-9003) dimensions in millimeters a b c c d dambar removal protrusion (16x) metallic protrusion, electrically connected to pin 4 and substrate (both sides) thermoplastic molded lead bar for alignment during shipment active area depth 0.43 mm ref branded face standard branding reference view = supplier emblem l = lot identifier n = last three numbers of device part number y = last two digits of year of manufacture w = week of manufacture lllllll yyww nnn branding scale and appearance at supplier discretion 0.38 +0.06 ?0.04 e f f f e e2 e1 1.10 1.10 hall elements (e1, e2); not to scale
two-wire, zero speed differential gear tooth sensor ic ATS685LSH 15 allegro microsystems, inc. 115 northeast cutoff worcester, massachusetts 01615-0036 u.s.a. 1.508.853.5000; www.allegromicro.com copyright ?2011, allegro microsystems, inc. allegro microsystems, inc. reserves the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be required to per- mit improvements in the per for mance, reliability, or manufacturability of its products. before placing an order, the user is cautioned to verify that the information being relied upon is current. allegro?s products are not to be used in life support devices or systems, if a failure of an allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system. the in for ma tion in clud ed herein is believed to be ac cu rate and reliable. how ev er, allegro microsystems, inc. assumes no re spon si bil i ty for its use; nor for any in fringe ment of patents or other rights of third parties which may result from its use. for the latest version of this document, visit our website: www.allegromicro.com

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