Preliminary Data Sheet Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Analog Speed Sensor with Integrated Filter Capacitor Package K, 4-pin SIP The A1421, A1422, and A1423 are ac-coupled Hall-effect sensors which include monolithic integrated circuits that switch in response to changing differential magnetic fields created by rotating ring magnets, or when coupled with a magnet, by ferrous targets. This family of devices also includes an integrated capacitor, providing the high accuracy of analog sensing without an external filter capacitor. This reduces cost and components, while improving the reliability of the final sensor solution. The magnetic field changes are sensed by two integrated Hall transducers and then are differentially amplified on the chip. Differential sensing provides immunity to radial vibration, within the device operating air gap range, by rejection of common-mode signal changes. Steady-state system offsets are eliminated using an on-chip differential bandpass filter with integrated capacitor. This filter also provides relative immunity to interference from electromagnetic sources. The device utilizes advanced temperature compensation for the high-pass filter, sensitivity, and Schmitt trigger switchpoints to guarantee optimal operation to low frequencies over a wide range of air gaps and temperatures. 1 2 3 4 Each device includes a voltage regulator, two Hall transducers, temperature compensating circuitry, a low-level amplifier, bandpass filter, Schmitt trigger, and an output driver. The on-board regulator permits operation with supply voltages from 4.0 to 26.5 V. The output stage can switch 20 mA over the full frequency response range of the sensor, and is compatible with TTL and CMOS logic circuits. Continued on next page. 1. VCC 2. VOUT 3. Test pin, tie to GND 4. GND ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC .......................................... 28 V Reverse-Supply Voltage, VRCC ........................ –18 V Output Current, IOUT .......................................25 mA Reverse-Output Current, IROUT.....................–50 mA Reverse-Output Voltage, VROUT ...................–50 mA Operating Temperature Ambient (L) , TA......................... –40ºC to 150ºC Maximum Junction, TJ(max)........................165ºC Storage Temperature, TS .................. –65ºC to 170ºC Features and Benefits • • • • • • • • • • Integrated tracking capacitor Senses motion of ring magnet or ferrous targets Wide operating temperature range Operation with frequency of sensed transitions from 20 Hz to 30 kHz EMI/ESD-resistant Large effective air gaps 4.0 to 26.5 V operating range Output compatible with both TTL and CMOS logic families Reverse battery protection Resistant to mechanical and thermal stress Engineering samples available on a limited basis. Contact your local sales or applications support office for additional information. A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor The devices in this family differ from each other in their switchpoint specifications and their switching polarity. The A1421 has a small hysteresis and asymmetrical switchpoints, with one switchpoint at the zero-crossing. The A1422 has a small hysteresis and symmetrical switchpoints, both near the zero-crossing. The A1423 offers high vibration immunity, by means of its larger hysteresis, establishing symmetrical switchpoints further from the zero-crossing. The output polarity is shown in the Product Selection Guide table. This variety of options provides flexibility for achieving solutions for a wide range of applications, including automotive transmission and crankshaft speed sensing. The device package has an operating ambient temperature range –40 °C to 150°C (suffix L), and is provided in a 4-pin plastic SIP (part number suffix K). Product Selection Guide Use the following complete part numbers when ordering: Output Switching at BDIFF = 0 Part Number Switchpoints Hysteresis Symmetry BDiff Increasing BDiff Decreasing BOP(typ) (G) BRP (G) BHys (typ) (G) BOP(max)+ BRP(min) (G) BOP(typ)+ BRP(typ) (G) BOP(min)+ BRP(max) (G) A1421LK Low (On) to High (Off) High (Off) to Low (On) 15 0 15 15 15 7.5 A1422LK High (Off) to Low (On) Low (On) to High (Off) 15 –15 30 0 0 0 A1423LK High (Off) to Low (On) Low (On) to High (Off) 65 –65 130 0 0 0 2 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor Functional Block Diagram V+ VCC (Pin 1) Regulator Dual Hall Transducers 0.1 uF Bandpass Filter Integrated Tracking Capacitor Hall Amp Test Pin (Pin 3) Diagnostic Circuitry Gain Stage Dual Comparators VOUT (Pin 2) Pulse Generation Logic GND (Pin 4) 3 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor OPERATING CHARACTERISTICS Valid at TA = – 40ºC to 150ºC, TJ ≤ 165°C; over operational air gap range and VCC within operating range, unless otherwise noted. Typical operating parameters: VCC = 12 V and TA = 25°C. Characteristic Symbol Test Conditions Min. Typ. Max. Units 4.0 12.0 26.5 V – 4.2 7.0 mA – 140 400 mV – – 5 µA ELECTRICAL CHARACTERISTICS Supply Voltage VCC Supply Current ICC Output Saturation Voltage Output Leakage Current Operating; TJ < TJ(max) VOUT(SAT) ISINK = 20 mA IOFF VOUT = 24 V, Bdiff = 0 PROTECTION COMPONENT CHARACTERISTICS Reverse Supply Current IRCC VCC = –18 V – – –1 mA Supply Zener Current IZCC VCC = 28 V – – 10 mA Supply Zener Clamp Voltage VZCC ICC = 10 mA1, TA = 25°C 28 33 37 V Output Zener Current IZOUT VOUT = 28 V – – 3 mA Output Zener Clamp Voltage VZOUT IOUT = 3 mA, TA = 25°C 28 – – V – – 50 mA t < tR – High – V tPO VCC > VCC(min) – 4.5 9 ms Output Short Circuit Current Limit IOUT(lim) RESPONSE CHARACTERISTICS Power-On State Power-On Time2,6 Settling Time3,6 POS tS fBdiff ≥ 100 Hz 0 – 50 ms Response Time6 tR Equal to tPO + tS; fBdiff ≥ 100 Hz 4.5 – 59 ms Upper Corner Frequency fcu –3 dB, single pole 30 – – kHz Lower Corner Frequency fcl –3 dB, single pole – – 20 Hz OUTPUT CHARACTERISTICS Output Rise Time4 trise RPU = 1 kΩ, C = 10 pF – – 200 ns Output Fall Time tfall RPU = 1 kΩ, ISINK = 20 mA, C = 10 pF – – 200 ns Continued on next page. 4 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Preliminary - Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Speed Sensor with Integrated Filter Capacitor OPERATING CHARACTERISTICS, continued Valid at TA = – 40ºC to 150ºC, TJ ≤ 165°C; over operational air gap range and VCC within operating range, unless otherwise noted. Typical operating parameters: VCC = 12 V and TA = 25°C. Characteristic Symbol Test Conditions Min. Typ. Max. Units MAGNETIC CHARACTERISTICS5 Operate point Release Point Hysteresis Applied Magnetic Field7 BOP6 BRP 6 BHYS6 Bdiff 1421, Bdiff increasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p 0.0 15.0 27.5 G 1422, Bdiff increasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p 5.0 15.0 35.0 G 1423, Bdiff increasing, fBdiff = 200 Hz, Bdiff = 200 Gp-p 10.0 65.0 100.0 G 1421, Bdiff decreasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p -12.5 0.0 7.5 G 1422, Bdiff decreasing, fBdiff = 200 Hz, Bdiff = 50 Gp-p -35.0 -15.0 -5.0 G 1423, Bdiff decreasing, fBdiff = 200 Hz, Bdiff = 200 Gp-p -100.0 -65.0 -10.0 G 1421, fBdiff = 200 Hz, Bdiff = 50 Gp-p 5 15 35 G 1422, fBdiff = 200 Hz, Bdiff = 50 Gp-p – 30 – G 1423, fBdiff = 200 Hz, Bdiff = 200 Gp-p – 130 – G Differential p-p magnetic field – – 1250 G 1Equivalent to I CC(max) + 3 mA. required to initialize device. 3Time required for the output switchpoints to be within specification. 4Output Rise Time will be dominated by the RC time constant. 5For lower frequencies, the absolute values of B , B , and B OP RP HYS may decrease due to delay induced by the high-pass filter. 6 See Definitions of Terms section. 7 Exceeding the maximum magnetic field may result in compromised absolute accuracy. 2Time 5 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions Minimum-K PCB (single-sided with copper limited to solder pads) RθJA Package Thermal Resistance Power Derating Curve TJ(max) = 165ºC; ICC = ICC(max) 30 VCC(max) 24 22 20 18 16 14 Minimum-K PCB (RθJA = 177 ºC/W) 8 6 VCC(min) 4 2 0 20 40 60 80 100 120 140 160 180 Power Dissipation, PD (m W) Maximum Allowable VCC (V) 26 10 Typ. 177 – Max Units – ºC/W Maximum Power Dissipation, PD(max) TJ(max) = 165ºC; VCC = VCC(max); ICC = ICC(max) 28 12 Min. 900 850 800 750 700 650 600 550 500 450 400 350 300 250 200 150 100 50 0 M (R inim θJ 20 40 60 A u = m-K 17 P 7 C ºC B /W ) 80 100 120 Temperature (°C) 140 160 180 Definitions of Terms The following provide additional information about some of the parameters cited in the Operating Characteristics table. For additional information, visit the Allegro Web site at www.allegromicro.com. Applied Magnetic Field, Bdiff – The differential magnetic flux density which is calculated as the arithmetic difference of the flux densities observed by each of the two Hall elements. Output Off Switchpoint (Operate Point), BOP – The value of increasing differential magnetic flux density at which the device output switches from low to high (A1421) or high to low (A1422 and A1423). Output On Switchpoint (Release Point), BRP – The value of decreasing differential magnetic flux density at which the device output switches from high to low (A1421) or from low to high (A1422 and A1423). Power-On Time, tPO – The time needed by the device, after power is applied, to initialize all circuitry necessary for proper operation. Settling Time, tS – The time required by the device, after tPO, and after a valid magnetic signal has been applied, to provide proper output transitions. Settling time is a function of magnetic offset, offset polarity, signal phase, signal frequency, and signal amplitude. Response Time, tR – The total time required for generating zerocrossing output transitions after power-up (the sum of power-on time and settling time). 6 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor Empirical Results 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 –50 VCC (V) 4.5 12.0 20.0 0 50 100 150 Current (mA) 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 –50 ICC(OFF) by VCC 200 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 Over TA Range TA (ºC) 150 25 –40 0 5 ICC(ON) by TA ICC(ON) by VCC Over VCC Range VCC (V) 4.5 12.0 20.0 0 50 100 150 200 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 TA (ºC) 150 25 –40 0 5 100 150 Voltage (mV) 4.5 12.0 20.0 50 10 15 20 25 VOUT(SAT) by VCC VCC (V) 0 25 Supply Voltage, VCC (V) Over VCC Range; ISINK = 20 mA Ambient Temperature, TA (ºC) 20 Over TA Range VOUT(SAT) by TA Voltage (mV) 15 Supply Voltage, VCC (V) Ambient Temperature, TA (ºC) 500 450 400 350 300 250 200 150 100 50 0 –50 10 Ambient Temperature, TA (ºC) Current (mA) Current (mA) Current (mA) ICC(OFF) by TA Over VCC Range 200 500 450 400 350 300 250 200 150 100 50 0 0 Over TA Range; ISINK = 20 mA TA (ºC) 150 25 –40 5 10 15 20 25 Supply Voltage, VCC (V) Continued on next page. 7 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Preliminary - Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Speed Sensor with Integrated Filter Capacitor Simulation Results Continued on next page. 8 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Preliminary - Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Speed Sensor with Integrated Filter Capacitor Simulation Results, continued Continued on next page. 9 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Preliminary - Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Speed Sensor with Integrated Filter Capacitor Simulation Results, continued Continued on next page. 10 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Preliminary - Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Speed Sensor with Integrated Filter Capacitor Simulation Results, continued 11 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor Sensor Evaluation: EMC Characterization Please contact Allegro MicroSystems for EMC performance information. (EMC test results are available after review of first silicon.) Test Name Reference Specification ESD – Human Body Model* AEC-Q100-002 ESD – Machine Model AEC-Q100-003 Conducted Transients ISO 7637-1 Direct RF Injection ISO 11452-7 Bulk Current Injection ISO 11452-4 TEM Cell ISO 11452-3 *ESD test is done with no external components. Vs R2 C1 1 R1 VCC 4 GND A1421, A1422, or A1423 VOUT 2 C2 Test 3 Component R1* R2 C1 C2 Value 1 100 0.1 0.1 Units kΩ Ω µF ηF *Pull-up resistor not required for protection but for normal operation. Recommended EMC test circuit. Test circuit recommended configuration may change after evaluation of first silicon. 12 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor Applications Information the other a negative hysteresis, BHYS2. Therefore, one comparator switches at the BOP crossing on an increasing differential signal and the other switches at the BRP crossing on a decreasing differential signal. The hysteresis on each comparator precludes false switching on noise or target jitter. The A1421, A1422, and A1423 are versatile high-precision differential sensing devices that can be used in a wide range of applications. Proper choice of the target material and shape, magnet material and shape, and assembly techniques enables large working air gaps and high switchpoint accuracy over the device operating temperature range. The behavior is similar for the A1422 and the A1423. The switchpoints are as shown in the magnetic charactersitics table, and the output polarity is inverted. This is illustrated in figure 2, on the next page. Sensor Operation The device sensor IC contains two integrated Hall transducers that are used to differentially sense a magnetic field across the surface of the IC. Referring to figure 1, which shows curves for the A1421 as an example, the trigger switches the output when the differential magnetic field crosses the BOP level while increasing in strength (referred to as the positive direction). In the example, the A1421 output voltage switches high (off), and switches the output low (on) when the differential magnetic field crosses BRP while decreasing (the negative direction). Start-up During power-on time, tPO, the output signal, VOUT, is high. Beyond this time, if the applied magnetic field, Bdiff, is smaller than BHYS, the switching state and VOUT polarity are indeterminate. VOUT will be valid for Bdiff > BHYS, after the additional settling time, tS, has also elapsed. Delay The operation is achieved through the use of two separate comparators. One comparator has a positive hysteresis, BHYS1, and The bandpass filter induces delay in the output signal, VOUT, relative to the applied magnetic field, Bdiff. Simulation data shown BRP(typ)1421 BHYS1 B OP(typ)1421 Applied Magnetic Field, Bdiff A 15.0 0.0 A BHYS2 Comparator 1, A1421 Comparator 2, A1421 1421 Switching State Off On Off 1421 Output Signal, VOUT Figure 1. Typical output characteristics with dual comparator operation. The example shown is for the A1421. Characteristics shown without delay, see characteristic data charts for delay and phase shift contributions. 13 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A1421, A1422, A1423 Preliminary - Subject to Change Without Notice June 16, 2004 High Accuracy Speed Sensor with Integrated Filter Capacitor in the Characteristic Data section quantify the effect of the input signal amplitude on the phase shift of the output. Positive values of delay indicate a lagging oputput whle negative values indicate a leading output. VCC AC-Coupled Operation Steady-state magnet and system offsets are eliminated using an on-chip differential bandpass filter. The upper and lower cut-off frequencies of this patented filter are set using an internal integrated capacitor. The differential structure of this filter improves the ability of the IC to reject single-ended noise on the GND or VCC line and, as a result, makes it more resistant to EMI (electromagnetic interference) typically seen in hostile remote-sensing environments. Power Supply Protection The A1425 contains an on-chip voltage regulator and can operate over a wide supply voltage range. In applications that operate the device from an unregulated power supply, transient protection must be added externally. For applications using a regulated line, EMI/RFI protection may still be required. The circuit shown in figure 3 is the most basic configuration required for proper device operation. 1 RPU 0.1 uF 4 A1421, A1422, or A1423 VOUT 2 3 Figure 3. Basic application circuit. A pull-up resistor, RPU, is required with the output driver. B OP(typ)1423 65.0 BOP(typ)1421, 1422 Applied Magnetic Field, Bdiff 15.0 0.0 –15.0 –65.0 BRP(typ)1421 B RP(typ)1422 B RP(typ)1423 1421 Switching State and Output Signal, VOUT 1422 Switching State and Output Signal, VOUT 1423 Switching State and Output Signal, VOUT Off On On On Off Off On Off On t+ Figure 2. Comparative typical output characteristics. This chart illustrates the switchpoints and the output polarities of the A1421, A1422, and the A 1423. Characteristics shown without delay, see characteristic data charts for delay and phase shift contributions. 14 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Preliminary - Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Speed Sensor with Integrated Filter Capacitor Power Derating Example 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.) Reliability for VCC at TA = 150°C, package L-I1, using minimumK PCB 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) ∆T = PD × RθJA (2) TJ = TA + ∆T (3) 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) = 7.0 mA. Calculate the maximum allowable power level, PD(max). First, invert equation 3: ∆Tmax = 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) = ∆Tmax ÷ RθJA = 15°C ÷ 177 °C/W = 91 mW Finally, invert equation 1 with respect to voltage: VCC(est) = PD(max) ÷ ICC(max) = 91 mW ÷ 7.0 mA = 13 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 = 4.2 mA, and RθJA = 177 °C/W, then: PD = VCC × ICC = 12 V × 4.2 mA = 50 mW ∆T = PD × RθJA = 50 mW × 177 °C/W = 9°C TJ = TA + ∆T = 25°C + 9°C = 34°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. 15 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Preliminary - Subject to Change Without Notice June 16, 2004 A1421, A1422, A1423 High Accuracy Speed Sensor with Integrated Filter Capacitor Package K, 4-pin SIP The products described herein are manufactured under one or more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283; 5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719; 5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents pending. Allegro MicroSystems, Inc. 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 products are not authorized for use as critical components in life-support devices or systems without express written approval. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. Copyright © 2004 Allegro MicroSystems, Inc. 16 A1421-DS Rev. 0 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com