A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Features and Benefits Description •4.0 to 26.5 V supply operating range •Minimum differential field 20 Gpk-pk •Running mode calibration for continuous optimization •Single chip IC for high reliability •Precise duty cycle signal throughout operating temperature range •Large operating air gaps •Automatic Gain Control (AGC) for air-gap–independent switchpoints •Automatic Offset Adjustment (AOA) for signal processing optimization •True zero-speed operation •Undervoltage lockout •Reverse battery protection •Scan and IDDQ for increased test coverage The A1468 is an optimized Hall effect sensing IC that provides a user-friendly solution for digital ring-magnet sensing, or when coupled with a magnet, ferromagnetic target sensing, in three-wire applications. The small device package can be easily assembled into applications for use in conjunction with a wide variety of target shapes and sizes. Package: 4-pin SIP (suffix K) The integrated circuit incorporates dual Hall effect elements with a 2.2 mm spacing and signal processing that switches in response to differential magnetic signals created by ringmagnet poles. The circuitry contains a sophisticated digital circuit to reduce system offsets, to calibrate the gain for airgap–independent switchpoints, and to achieve true zero-speed operation. Signal optimization occurs at power-on through the combination of offset and gain adjust, and is maintained throughout the operating time with the use of a running-mode calibration. The running-mode calibration provides immunity to environmental effects such as micro-oscillations of the target or sudden air gap changes. The device is ideally suited to obtaining speed and duty cycle information in ring-magnet–based speed, position, and timing applications, such as in speedometers. The A1468 is available in a 4-pin SIP (suffix K). The package is lead (Pb) free, with 100% matte tin leadframe plating. Not to scale Functional Block Diagram VCC E1 Hall Amplifier ∑ Internal Regulator Gain E2 Automatic Offset Adjustment (AOA) Control AOA DAC Automatic Gain Control (AGC) AGC DAC Tracking DAC Peak Hold OUT + – Test Signals TEST A1468-DS, Rev. 1 Current Limit GND Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration A1468 Selection Guide Part Number Package Packing* A1468LK-T 4-pin through hole SIP *Contact Allegro™ for additional packing options. Bulk, 500 pieces per bag Operating Ambient Temperature Range, TA (°C) -40 to 150 Absolute Maximum Ratings Characteristic Symbol Forward Supply Voltage VCC Reverse Supply Voltage VRCC Notes Rating Refer to Power Derating Curves chart Unit 28 V –18 V Output Current IOUT 30 mA Reverse Output Current IROUT –50 mA Reverse Output Voltage VROUT –0.5 V Output Off Voltage VOUT 28 V Operating Ambient Temperature TA –40 to 150 ºC Maximum Junction Temperature TJ(max) 165 ºC Tstg –65 to 170 ºC Storage Temperature Pin-out Diagram L temperature range Terminal List Table Number 1 2 3 Name Function 1 VCC 2 VOUT Supply voltage Output 3 TEST Test pin, float 4 GND Ground 4 Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration OPERATING CHARACTERISTICS Valid throughout operating voltage and ambient temperature ranges, typical data applies at VCC = 12 V and TA = 25°C; unless otherwise specified Characteristics Symbol Test Conditions Min. Typ. Max. Unit1 Operating, TJ ≤ 165°C 4 – 26.5 V VCC = 0 → VCC(min) + 1 V and VCC(min) + 1 V → 0 V – – VCC(min) V 3.0 5.0 7.5 mA VOUT, connected as in figure 6 – High – V VCC > VCC(min) – – 2.3 ms ICC = ICC(max) + 3 mA, TA = 25 °C 38 – – V mA mA Electrical Characteristics Supply Voltage2 Undervoltage Lockout Supply Current VCC VCC(uv) ICC VCC > VCC(min) Power-On Characteristics Power-On State Power-On Time3 POS tPO Transient Protection Characteristics Supply Zener Clamp Voltage Supply Zener Current Reverse Supply Current VZ(supply) IZ(supply) IRCC Vsupply = 38 V – – ICC(max) +3 VRCC = –18 V, TJ < TJ(max) – – –1 Output Zener Clamp Voltage VZ(output) IOUT = 3 mA, TA = 25°C 28 – – V Output Zener Current IZ(output) VOUT = 28 V – – 3 mA Output Current Limit IOUT(lim) 30 – 85 mA IOUT(sink) = 20 mA – 220 400 mV VOUT = 24 V, output off – – 10 µA RPU = 1 kΩ, VPU = 20 V, COUT = 10 pF – 2 – µs 20 – 1200 G – 120 – mV 3 – 10 G – 120 – mV 3 – 10 G 0 – 10 kHz Output Stage Characteristics Output Saturation Voltage Output Leakage Current Output Fall Time VOUT(sat) IOFF tf Performance Characteristics Operating Magnetic Signal Range BDIFF Peak-to-peak of differential signal; operation within specification Operate Point4 BOP See figure 5 Release Point4 BRP See figure 5 Operating Frequency fOP Analog Signal Bandwidth BW Equivalent to f = –3 dB 20 – – kHz Initial Calibration Cycle5 ncal Output rising edges before calibration is completed, 0 offset, fOP ≤ 200 Hz – – 3 edge Output Duty Cycle Precision DOUT Using a pure sine magnetic signal, with fOP and BDIFF within specification – – ±15 % Output Period Precision TOUT Using pure sine magnetic signal with BDIFF = 50 Gpk-pk and fOP = 1 kHz – 0.3 – % Output switching only – – ±100 G Allowable User Induced Differential Offset BDIFFEXT 11 G (gauss) = 0.1 mT (millitesla). voltage operation must not exceed maximum junction temperature. Refer to Power Derating Curves chart. 3Time required to initialize device. Power-On Time includes the time required to complete the internal automatic offset adjust. The DAC is then ready for peak acquisition. 4Values in G are based on device in maximum gain setting. 5Non-uniform magnetic profiles may require additional output pulses before calibration is complete. 2Maximum Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Thermal Characteristics may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions* RθJA Package Thermal Resistance On single-layer PCB with copper limited to solder pads Value Unit 177 ºC/W *Additional thermal information available on the Allegro website. Maximum Allowable VCC (V) Power Derating Curves 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 VCC(max) 177ºC/W VCC(min) 20 40 60 80 100 120 140 160 180 Ambient Temperature, TA (ºC) Power Dissipation versus Ambient Temperature 900 Power Dissipation, PD (mW) 800 700 600 500 177 °C/W 400 300 200 100 0 20 40 60 80 100 120 140 160 180 Ambient Temperature, TA (ºC) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration A1468 Characteristic Performance Supply Current (Output On) versus Temperature 7 6 Supply Current, Icc (mA) 6 Supply Current, Icc (mA) Supply Current (Output On) versus Supply Voltage 7 5 4 Vcc (V) 3 4 2 12 1 5 4 TA (°C) 3 -40 25 2 85 1 26.5 150 0 0 -50 -25 0 25 50 75 100 125 0 150 5 Ambient Temperature,( TA °C) 25 30 6 Supply Current, Icc (mA) Supply Current, Icc (mA) 20 Supply Current (Output Off) versus Supply Voltage 7 6 5 4 Vcc (V) 3 4 2 12 1 -50 -25 0 25 50 75 100 125 5 4 TA (°C) 3 -40 25 2 85 1 26.5 0 150 0 150 0 5 Ambient Temperature, TA (°C) Output Saturation Voltage versus Temperature 500 IOUT(mA) 450 10 15 20 25 400 350 300 250 200 150 100 50 0 -50 -25 0 25 50 75 100 Ambient Temperature, TA (°C) 10 15 20 25 30 Supply Voltage, Vcc (V) Output Saturation Voltage, VOUT(sat) (V) Output Saturation Voltage, VOUT(sat) (V) 15 Supply Voltage, Vcc (V) Supply Current (Output Off) versus Temperature 7 10 125 150 Output Saturation Voltage versus Output Current 500 TA (°C) 450 400 -40 350 25 300 85 250 150 200 150 100 50 0 0 5 10 15 20 25 30 Output Current, I OUT(mA) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration A1468 Output Fall Time versus Temperature Output Fall Time, t f (µs) 3 2.5 2 1.5 1 IOUT (mA) 10 0.5 20 0 -25 0 25 50 75 100 Ambient Temperature, TA (°C) 125 150 Output Duty Cycle Precision versus Temperature at Air Gap* = 3mm 16 fOP (Hz) 14 20 500 1000 2000 12 10 8 6 4 2 0 -50 -25 0 25 50 75 100 Output Duty Cycle Precision versus Frequency at Air Gap* = 3mm 16 Output Duty Cycle Precision, DOUT (%) Output Duty Cycle Precision, DOUT (%) -50 125 14 TA (°C) 12 -40 10 25 8 85 6 150 4 2 0 150 0 Output Duty Cycle Precision versus Air Gap* at TA = 25°C 16 14 fOP (Hz) 12 20 500 1000 2000 10 8 6 4 2 0 0 1 2 Air Gap (mm) 3 4 Output Duty Cycle Precision, DOUT (%) Output Duty Cycle Precision, DOUT (%) Ambient Temperature, TA (°C) 500 1000 1500 Operating Frequency, fOP (Hz) 2000 Output Duty Cycle Precision versus Frequency at TA = 25°C 16 Air Gap*(mm) 14 0.5 1.0 1.5 2.0 2.5 3.0 3.5 12 10 8 6 4 2 0 0 500 1000 1500 2000 Operating Frequency, fOP (Hz) *Air gap defined as the distance between the front face of the A1468 package and the Allegro Reference Target 60-0 ring magnet Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration A1468 Characteristic Allowable Air Gap Movement Allowable Air Gap Movement from TEAGCAL* 2.0 ∆TEAGOUT (mm) 1.5 1.0 0.5 0 -0.5 -1.0 0 0.5 1.0 1.5 2.0 ∆TEAGIN (mm) 2.5 3.0 3.5 *Data based on study performed using Allegro Reference Target 60-0 ring magnet, and applicable to ring magnet targets with similar magnetic characteristics. The colored area in the chart above shows the region of allowable air gap movement within which the device will continue output switching. The output duty cycle is wholly dependent on the target’s magnetic signature across the air gap range of movement, and may not always be within specification throughout the entire operating region (to AG(OPmax)). panel a) within the range defined by an increase of ΔTEAGOUT = 0.35 mm (shown in panel b), and a decrease of ΔTEAGIN = 0.65 mm (shown in panel c). This case is plotted with an “x” in the chart above. Please note that after extreme cases of decrease in air gap, the device may not switch when the air gap resumes the nominal value. For example, if ΔTEAGIN = 2.75 mm, the chart shows ΔTEAGOUT = –0.5 mm, meaning that the device can now switch only in the air gap range of 0.5 to 2.75 mm inward from the nominal air gap. The axis parameters for the chart are defined in the drawings below. As an example, assume the case where the air gap is allowed to vary from the nominal installed air gap (TEAGCAL , (a) (b) A1468 (c) TEAGCAL TEAG OUT A1468 TEAG IN A1468 Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Functional Description Sensing Technology The single-chip differential Hall effect sensor IC possesses two Hall elements, which sense the magnetic profile of the ring magnet simultaneously, but at different points (spaced at a 2.2 mm pitch), generating a differential internal analog voltage, VPROC , that is processed for precise switching of the digital output signal. The Hall IC is self-calibrating and also possesses a temperature compensated amplifier and offset compensation 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 compensation circuitry. The Hall transducers and signal processing electronics are integrated on the same silicon substrate, using a proprietary BiCMOS process. Target (Ring Magnet) S S N N Element Pitch Hall Element 2 Hall Element 1 Hall IC (Pin 4 Side) (Pin 1 Side) Figure 1: Relative motion of the target is detected by the dual Hall elements mounted on the Hall IC. Target Profiling An operating device is capable of providing digital information that is representative of the magnetic features on a rotating target. The waveform diagram shown in Figure 3 presents the automatic translation of the magnetic profile to the digital output signal of the device. Output Polarity Figure 3 shows the output polarity for the orientation of target and device shown in Figure 2. The target direction of rotation shown is: perpendicular to the leads, across the face of the device, from the pin 1 side to the pin 4 side. This results in the device output switching from low to high as the leading edge of a north magnetic pole passes the device face. In this configuration, the device output voltage switches to its high polarity when a north pole is the target feature nearest to the device. If the direction of rotation is reversed, then the output polarity inverts. Branded Face of K Package Rotating Target S N S N S SN Pin 1 N Pin 4 Figure 2: This left-to-right (pin 1 to pin 4) direction of target rotation results in a high output signal when a target north pole is nearest the face of the device (see figure 3). A right-to-left (pin 4 to pin 1) rotation inverts the output signal polarity. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Figure 3: Output Profile of a Ring Magnet Target for the Polarity Indicated in Figure 2. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Automatic Gain Control (AGC) This feature allows the device to operate with an optimal internal electrical signal, regardless of the differential signal amplitude (within the BDIFF and BDIFFEXT specifications). During calibration, the device determines the peak-to-peak amplitude of the signal generated by the target. The gain of the device is then automatically adjusted. Figure 4 illustrates the effect of this feature. During running mode, the AGC continues to monitor the system amplitude, reducing the gain if necessary; see the Device Operation section for more details. Automatic Offset Adjust (AOA) The AOA is patented circuitry that automatically compensates for the effects of chip, magnet, and installation offsets. This circuitry is continuously active, including both during calibration mode and running mode, compensating for offset drift. Continuous operation also allows it to compensate for offsets induced by temperature variations over time. Digital Peak Detection A digital DAC tracks the internal analog voltage signal, VPROC, and is used for holding the peak value of the internal analog signal. In the example shown in Figure 5, the DAC would first track up with the signal and hold the upper peak’s value. When VPROC drops below this peak value by BOP , the device hysteresis, the output would switch and the DAC would begin tracking the signal downward toward the negative VPROC peak. After the DAC acquires the negative peak, the output will again switch states when VPROC is greater than the peak by the value BRP . At this point, the DAC tracks up again and the cycle repeats. The digital tracking of the differential analog signal allows the device to achieve true zero-speed operation. Target Ring Magnet N S N S V+ Internal Differential Analog Signal Response, without AGC AGLarge AGSmall V+ Internal Differential Analog Signal Response, with AGC AGSmall AGLarge Figure 4: Automatic Gain Control (AGC). The AGC function corrects for variances in the air gap. Differences in the air gap affect the magnetic gradient, but AGC prevents that from affecting device performance, as shown in the lowest panel. V+ Internal Differential Analog Signal, VPROC 0 BOP BOP BRP BRP V– VCC Device Output, VOUT VOUT(sat) Figure 5: The peaks in the resulting differential signal are used to set the operate, BOP , and release, BRP , switchpoints. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 10 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Power Supply Protection The device contains an on-chip regulator and can operate throughout a wide VCC range. For devices that must be operated from an unregulated 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 required for compliance with various EMC specifications. Refer to figure 6 for an example of a basic application circuit. event could be caused by thermal transients, but would require a static applied magnetic field, proper signal polarity, and particular direction and magnitude of internal signal drift. Undervoltage Lockout When the supply voltage falls below the undervoltage lockout voltage, VCC(uv) , the device enters Reset, where the output state returns to the Power-On State (POS) until sufficient VCC is supplied. Calibration Mode The calibration mode allows the device to Assembly Description This device is integrally molded into a plastic body that has been optimized for size, ease of assembly, and manufacturability. High operating temperature materials are used in all aspects of construction. Device Operation Each operating mode is described in detail below. Power-On When power (VCC > VCC(min)) is applied to the device, a short period of time is required to power the various portions of the IC. During this period, the A1468 powers-on in the high voltage state, VOUT(high). After power-on, there are conditions that could induce a change in the output state. Such an Initial Offset Adjust The device initially cancels the effects of chip, magnet, and installation offsets. After offsets have been cancelled, the digital tracking DAC is ready to track the signal and provide output switching. The period of time required for both Power-On and Initial Offset Adjust is defined as the PowerOn Time. automatically select the proper signal gain and continue to adjust for offsets. The AGC is active, and selects the optimal signal gain based on the amplitude of the VPROC signal. Following each adjustment to the AGC DAC, the Offset DAC is also adjusted to ensure the internal analog signal is properly centered. During this mode, the tracking DAC is active and output switching occurs, but the duty cycle is not guaranteed to be within specification. Running Mode After the Initial Calibration period, CI, estab- lishes a signal gain, the device moves to running mode. During running mode, the device tracks the input signal and gives an output edge for every peak of the signal. AOA remains active to compensate for any offset drift over time. The A1468 incorporates an algorithm for adjusting the signal gain during running mode. This algorithm is designed to optimize the VPROC signal amplitude in instances where the magnetic signal “seen” during the calibration period is not representative of the Vsupply RPU 1 kΩ VCC CBYP 0.1 µF A1468 TEST OUT GND VOUT COUT Figure 6: Typical Application Diagram Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration A1468 amplitude of the magnetic signal for the installed device air gap (see figure 7). Note that in this mode, the gain can be reduced but not increased, so this algorithm applies only to instances in which the magnetic signal amplitude during running is higher than that during calibration. 1 2 3 4 5 BOP Internal Differential Signal, VPROC BOP BRP BRP Device Electrical Output, VOUT Figure 7: Operation of Running Mode Gain Adjust • Position1. The device is initially powered-on. Self-calibration occurs. • Position 2. Small amplitude oscillation of the target sends an erroneously small differential signal to the device. The amplitude of VPROC is greater than the switching hysteresis (BOP and BRP), and the device output switches. • Position 3. The calibration period completes on the third rising output edge, and the device enters running mode. • Position 4. True target rotation occurs and the correct magnetic signal is generated for the installation air gap. The established signal gain is too large for the target rotational magnetic signal at the given air gap. • Position 5. Running mode calibration corrects the signal gain to an optimal level for the installation air gap. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 12 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Power Derating The device must be operated below the maximum junction temperature of the device, TJ(max). Under certain combinations of peak conditions, reliable operation may require derating supplied power or improving the heat dissipation properties of the application. This section presents a procedure for correlating factors affecting operating TJ. (Thermal data is also available on the Allegro MicroSystems Web site.) The Package Thermal Resistance, RθJA, is a figure of merit summarizing 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, RθJC, is relatively small component of RθJA. Ambient air temperature, TA, and air motion are significant external factors, damped by overmolding. The effect of varying power levels (Power Dissipation, PD), can be estimated. The following formulas represent the fundamental relationships used to estimate TJ, at PD. PD = VIN × IIN (1) ΔT = PD × RθJA (2) TJ = TA + ΔT(3) Example: Reliability for VCC at TA = 150°C, package K, using minimum-K PCB. Observe the worst-case ratings for the device, specifically: RθJA = 177°C/W, TJ(max) = 165°C, VCC(max) = 26.5 V, and ICC(max) = 7.5 mA. Calculate the maximum allowable power level, PD(max). First, invert equation 3: ΔTmax = TJ(max) – TA = 165 °C – 150 °C = 15 °C This provides the allowable increase to TJ resulting from internal power dissipation. Then, invert equation 2: PD(max) = ΔTmax ÷ RθJA = 15°C ÷ 177 °C/W = 85 mW Finally, invert equation 1 with respect to voltage: VCC(est) = PD(max) ÷ ICC(max) = 85 mW ÷ 7.5 mA = 11.3 V The result indicates that, at TA, the application and device can dissipate adequate amounts of heat at voltages ≤VCC(est). Compare VCC(est) to VCC(max). If VCC(est) ≤ VCC(max), then reliable operation between VCC(est) and VCC(max) requires enhanced RθJA. If VCC(est) ≥ VCC(max), then operation between VCC(est) and VCC(max) is reliable under these conditions. For example, given common conditions such as: TA= 25°C, VCC = 12 V, ICC = 5 mA, and RθJA = 177 °C/W, then: PD = VCC × ICC = 12 V × 5 mA = 60 mW ΔT = PD × RθJA = 60 mW × 177 °C/W = 10.6°C TJ = TA + ΔT = 25°C + 10.6°C = 35.6°C A worst-case estimate, PD(max), represents the maximum allowable power level (VCC(max) , ICC(max)), without exceeding TJ(max), at a selected RθJA and TA. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 13 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration A1468 Package K, 4-Pin SIP 5.21 +0.08 –0.05 B 45° E E 2.20 1.50 1.55 ±0.05 D 1.32 E 3.43 +0.08 –0.05 Mold Ejector Pin Indent NNNN YYWW E2 E1 Branded Face 2.16 MAX 45° C Standard Branding Reference View 0.84 REF N = Device part number Y = Last two digits of year of manufacture W = Week of manufacture A 1 2 3 For Reference Only, not for tooling use (reference DWG-9010) Dimensions in millimeters Dimensions exclusive of mold flash, gate burs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown 4 A Dambar removal protrusion (8X) 14.73 ±0.51 B Gate and tie burr area 0.41 +0.07 –0.05 0.38 +0.06 –0.03 C Branding scale and appearance at supplier discretion D Active Area Depth, 0.42 mm E Hall elements (E1 and E2), not to scale 1.27 NOM Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 14 A1468 Three-Wire True Zero-Speed Differential Peak-Detecting Sensor IC with Continuous Calibration Revision History Revision Current Revision Date 1 April 14, 2014 Description of Revision Revised Power Dreating Curve Copyright ©2011-2014, Allegro MicroSystems, LLC Allegro MicroSystems, LLC reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, 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 any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no responsibility for its use; nor for any infringement 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 Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 15