A1140, A1141, A1142, and A1143 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches Features and Benefits Description ▪ Chopper stabilization ▫ Low switchpoint drift over operating temperature range ▫ Low sensitivity to stress ▪ Factory programmed at end-of-line for optimized switchpoints ▪ On-chip protection ▫ Supply transient protection ▫ Reverse-battery protection ▫ On-board voltage regulator ▫ 3.5 to 24 V operation The A1140, A1141, A1142, and A1143 devices are sensitive, two-wire, unipolar, Hall effect switches that are factoryprogrammed at end-of-line to optimize magnetic switchpoint accuracy. These devices use a patented high frequency chopperstabilization technique, produced using the Allegro advanced BiCMOS wafer fabrication process, to achieve magnetic stability and to eliminate offset inherent in single-element devices exposed to harsh application environments. Packages: 3 pin SOT23W (suffix LH), and 3 pin SIP (suffix UA) Commonly found in a number of automotive applications, these switches are utilized to sense seat track position, seat belt buckle presence, hood/trunk latching, and shift selector position. Two-wire unipolar switches, such as the A1140/41/42/43 family, are particularly advantageous in price-sensitive applications because they require one less wire for operation than do switches with the more 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 narrow ranges. Any current level not within these ranges indicates a fault condition. The A1140/41/42/43 family of switches also Continued on the next page… Not to scale Functional Block Diagram V+ VCC Regulator To All Subcircuits Dynamic Offset Cancellation 0.01 uF Amp Sample and Hold Clock/Logic Low-Pass Filter GND Package UA Only A1140-DS, Rev. 8 GND Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Description (continued) features on-chip transient protection and a Zener clamp to protect against overvoltage conditions on the supply line. and switch HIGH otherwise. The other differences in the switches are their defined low current levels and magnetic switchpoints. The output currents of the A1141 and A1143 switch HIGH in the presence of a south (+) polarity magnetic field of sufficient strength, and switch LOW otherwise, as in the presence of a weak field or a north (–) polarity field. The other two devices in the family (A1140 and A1142) have an opposite output: the currents switch LOW in the presence of a south-polarity magnetic field of sufficient strength, All versions are offered in two package styles. The LH is a SOT23W, miniature low-profile package for surface-mount applications. The UA is a three-lead ultramini SIP for through-hole mounting. Each package is available in a lead (Pb) free version (suffix, –T) with 100% matte tin plated leadframe. Field-programmable versions also available: A1180, A1181, A1182, and A1183. Absolute Maximum Ratings Characteristic Symbol Supply Voltage VCC Reverse Supply Voltage Notes Rating Units 28 V VRCC –18 V Magnetic Flux Density B Unlimited G Operating Ambient Temperature TA Maximum Junction Temperature TJ(max) 165 ºC Tstg –65 to 170 ºC Storage Temperature Range E –40 to 85 ºC Range L –40 to 150 ºC Package LH, 3-pin SOT Package UA, 3-pin SIP 3 NC 1. VCC 2. No connection 3. GND 1 2 1. VCC 2. GND 3. GND 1 2 3 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Product Selection Guide A1140EUATI-T4 Yes Tape and Reel, 2000 pieces/reel Through Hole Operating Ambient Temperature, TA (°C) –40 to 85 A1140LUATI-T4 Yes Tape and Reel, 2000 pieces/reel Through Hole –40 to 150 A1141EUATI-T4 Yes Tape and Reel, 2000 pieces/reel Through Hole –40 to 85 –40 to 150 Part Number Pb-Free1 Packing2 Package A1141LUATI-T4 Yes Tape and Reel, 2000 pieces/reel Through Hole A1142ELHLT-T Yes Tape and Reel, 3000 pieces/reel Surface Mount A1142EUA-T Yes Bulk Bag, 500 pieces/bag A1142EUATI-T4 Yes Tape and Reel, 2000 pieces/reel A1142LLHLT-T Yes Tape and Reel, 3000 pieces/reel A1142LUA-T Yes Bulk Bag, 500 pieces/bag A1142LUATI-T4 Yes Tape and Reel, 2000 pieces/reel A1143ELHLT-T Yes Tape and Reel, 3000 pieces/reel A1143EUA-T Yes Bulk Bag, 500 pieces/bag A1143EUATI-T4 Yes Tape and Reel, 2000 pieces/reel A1143LLHLT-T Yes Tape and Reel, 3000 pieces/reel Through Hole Low 2 to 5 High Low –40 to 150 5 to 6.9 Surface Mount Through Hole Surface Mount Supply Current at Low Output, ICC(L) (mA) –40 to 85 Surface Mount Through Hole Output Level in South (+) Field3 –40 to 85 High A1143LUA-T Yes Bulk Bag, 500 pieces/bag –40 to 150 Through Hole Yes Tape and Reel, 2000 pieces/reel A1143LUATI-T4 1Pb-based variants are being phased out of the product line. (a) Certain variants cited in this footnote are in production but have been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because obsolescence in the near future is probable. Samples are no longer available. Status change: May 1, 2006. These variants include A1140EUATI, A1140LUATI, A1140LUATI, A1141EUA, A1141EUATI, A1141LLHLT, A1141LUA, A1141LUATI, A1142EUATI, A1142LUATI,A1142LLHLT, A1142LUA, A1143EUATI, A1143LUA , and A1143LUATI. (b) Certain variants cited in this footnote are in production but have been determined to be LAST TIME BUY. This classification indicates that the product is obsolete and notice has been given. Sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because of obsolescence in the near future. Samples are no longer available. Status date change October 31, 2006. Deadline for receipt of LAST TIME BUY orders is April 27, 2007. These variants include: A1142ELHLT, A1142EUA, A1143ELHLT, A1143EUA, and A1143LLHLT. 2Contact Allegro for additional packing options. 3South (+) magnetic fields must be of sufficient strength. 4Some restrictions may apply to certain types of sales. Contact Allegro for details. 5The sensors listed in this footnote are available only in limited distribution. Interested customers should contact the appropriate sales person or field application engineer for more information on availability. These variants include: A1140ELHLT-T, A1140EUA-T, A1140LLHLT-T, A1140LUA-T, A1141ELHLT-T, A1141EUA-T, A1141LLHLT-T, and A1141LUA-T. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 ELECTRICAL CHARACTERISTICS over the operating voltage and temperature ranges, unless otherwise specified Characteristic Supply Voltage1 Symbol Test Conditions Typ. Max. Units 3.5 – 24 V B>BOP for A1140; B<BRP for A1141 2 – 5 mA B>BOP for A1142; B<BRP for A1143 5 -– 6.9 mA B>BOP for A1141, A1143 B<BRP for A1140, A1142 12 -– 17 mA – – –1.6 mA VCC ICC(L) Supply Current 2 ICC(H) Reverse Supply Current Min. IRCC VRCC = –18 V Supply Zener Clamp Voltage VZSUPPLY ICC = ICC(L)(max) + 3 mA; TA = 25°C 28 – 40 V Supply Zener Clamp Current IZSUPPLY VZSUPPLY = 28 V – – ICC(L)(max) + 3 mA mA Capacitance of the oscilloscope performing the measurement = 20 pF – 36 – mA/μs – 200 – kHz CBYPASS = 0.01 μF – – 25 μs t < ton; VCC slew rate > 25 mV/μs – HIGH – – Output Slew Rate3 di/dt Chopping Frequency fC Power-On Time3 ton Power-On State5,6 POS 1V CC represents 2Relative values the generated voltage between the VCC pin and the GND pin. of B use the algebraic convention, where positive values indicate south magnetic polarity, and negative values indicate north magnetic polarity; therefore greater B values indicate a stronger south polarity field (or a weaker north polarity field, if present). 3Measured without bypass capacitor between VCC and GND. Use of a bypass capacitor results in slower current change. 3Measured with and without bypass capacitor of 0.01 μF. Adding a larger bypass capacitor causes longer Power-On Time. 5POS is defined as true only with a V CC slew rate of 25 mV / μs or greater. Operation with a VCC slew rate less than 25 mV / μs can permanently harm device performance. 6POS is undefined for t > t or B on RP < B < BOP . MAGNETIC CHARACTERISTICS over the operating voltage and temperature ranges, unless otherwise specified Characteristic Symbol Operate Point BOP Release Point BRP Hysteresis BHYS Test Conditions A1140, A1142 ICC = ICC(L) A1141, A1143 ICC = ICC(H) A1140, A1142 ICC = ICC(H) A1141, A1143 ICC = ICC(L) BHYS = BOP – BRP Min. Typ.* Max. Units 50 80 110 G 45 65 105 G 5 15 30 G *Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions, such as TA = 25°C and VCC = 12 V. Performance may vary for individual units, within the specified maximum and minimum limits. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 4 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Characteristic Data Supply Current (Low) versus Ambient Temperature at Various Levels of VCC (A1140 and A1141) Supply Current (Low) versus Ambient Temperature at Various Levels of VCC (A1142 and A1143) 10 10 8 8 6 VCC 3.5 V 12.0 V 24.0 V 4 ICC(L) (mA) ICC(L) (mA) VCC 2 0 –50 6 3.5 V 12.0 V 24.0 V 4 2 0 50 100 150 0 –50 200 0 Ambient Temperature, TA (°C) 50 100 150 200 Ambient Temperature, TA (°C) Supply Current (High) versus Ambient Temperature at Various Levels of VCC (A1140, A1141, A1142, and A1143) 20 18 ICC(H) (mA) VCC 16 3.5 V 12.0 V 24.0 V 14 12 10 –50 0 50 100 150 200 Ambient Temperature, TA (°C) Operate Point versus Ambient Temperature at Various Levels of VCC (A1140, A1141, A1142, and A1143) Switchpoint Hysteresis versus Ambient Temperature at Various Levels of VCC (A1140, A1141, A1142, and A1143) 110 10 100 8 VCC 3.5 V 12.0 V 24.0 V 80 70 6 3.5 V 12.0 V 24.0 V 4 2 60 50 –50 VCC BHYS (G) BOP (G) 90 0 50 100 Ambient Temperature, TA (°C) 150 200 0 –50 0 50 100 150 200 Ambient Temperature, TA (°C) Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 5 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions* RθJA Package Thermal Resistance Value Units Package LH, 1-layer PCB with copper limited to solder pads 228 ºC/W Package LH, 2-layer PCB with 0.463 in.2 of copper area each side connected by thermal vias 110 ºC/W Package UA, 1-layer PCB with copper limited to solder pads 165 ºC/W *Additional thermal information available on Allegro Web site. Maximum Allowable VCC (V) Power Derating Curve 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) 2-layer PCB, Package LH (RθJA = 110 ºC/W) 1-layer PCB, Package UA (RθJA = 165 ºC/W) 1-layer PCB, Package LH (RθJA = 228 ºC/W) 20 40 60 80 100 VCC(min) 120 140 160 180 Temperature (ºC) Power Dissipation, PD (m W) Power Dissipation versus Ambient Temperature 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 2l (R aye rP θJ C A = 11 B, P 0 º ac 1-la C/ ka W (R yer PC ) ge L θJA = B H 165 , Pac ºC/ kage W) UA 1-lay er P (R CB, θJA = 228 Packag ºC/W e LH ) 20 40 60 80 100 120 Temperature (°C) 140 160 180 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 6 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Functional Description Operation BRP BHYS (A) A1140, A1142 B+ 0 ICC(L) B– BRP BOP B– ICC(H) ICC ICC ICC(L) 0 I+ Switch to Low Switch to Low Switch to High ICC(H) Switch to High I+ in hysteresis allows clean switching of the output even in the presence of external mechanical vibration and electrical noise. The A1141 and A1143 devices switch with opposite polarity for similar BOP and BRP values, in comparison to the A1140 and A1142 (see figure 1). BOP The output, ICC, of the A1140 and A1142 devices switch low after the magnetic field at the Hall sensor exceeds the operate point threshold, BOP. When the magnetic field is reduced to below the release point threshold, BRP, the device output goes high. The differences between the magnetic operate and release point is called the hysteresis of the device, BHYS. This built- B+ BHYS (B) A1141, A1143 Figure 1. Alternative switching behaviors are available in the A114x device family. On the horizontal axis, the B+ direction indicates increasing south polarity magnetic field strength, and the B– direction indicates decreasing south polarity field strength (including the case of increasing north polarity). Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 7 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Chopper Stabilization Technique When using Hall-effect technology, a limiting factor for switchpoint accuracy is the small signal voltage developed across the Hall element. This voltage is disproportionally small relative to the offset that can be produced at the output of the Hall sensor. This makes it difficult to process the signal while maintaining an accurate, reliable output over the specified operating temperature and voltage ranges. Chopper stabilization is a unique approach used to minimize Hall offset on the chip. The patented Allegro technique, namely Dynamic Quadrature Offset Cancellation, removes key sources of the output drift induced by thermal and mechanical stresses. This offset reduction technique is based on a signal modulationdemodulation process. The undesired offset signal is separated from the magnetic field-induced signal in the frequency domain, through modulation. The subsequent demodulation acts as a modulation process for the offset, causing the magnetic fieldinduced signal to recover its original spectrum at baseband, while the dc offset becomes a high-frequency signal. The magneticsourced signal then can pass through a low-pass filter, while the modulated dc offset is suppressed. This configuration is illustrated in figure 2. The chopper stabilization technique uses a 200 kHz high frequency clock. For demodulation process, a sample and hold technique is used, where the sampling is performed at twice the chopper frequency (400 kHz). This high-frequency operation allows a greater sampling rate, which results in higher accuracy and faster signal-processing capability. This approach desensitizes the chip to the effects of thermal and mechanical stresses, and produces devices that have extremely stable quiescent Hall output voltages and precise recoverability after temperature cycling. This technique is made possible through the use of a BiCMOS process, which allows the use of low-offset, low-noise amplifiers in combination with high-density logic integration and sample-and-hold circuits. The repeatability of magnetic field-induced switching is affected slightly by a chopper technique. However, the Allegro highfrequency chopping approach minimizes the affect of jitter and makes it imperceptible in most applications. Applications that are more likely to be sensitive to such degradation are those requiring precise sensing of alternating magnetic fields; for example, speed sensing of ring-magnet targets. For such applications, Allegro recommends its digital sensor families with lower sensitivity to jitter. For more information on those devices, contact your Allegro sales representative. Regulator Hall Element Amp Sample and Hold Clock/Logic Low-Pass Filter Figure 2. Chopper stabilization circuit (Dynamic Quadrature Offset Cancellation) Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 8 A1140, A1141, A1142, and A1143 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches Application Information Typical Application Circuit The A114x family of devices must be protected by an external bypass capacitor, CBYP, connected between the supply, VCC, and the ground, GND, of the device. CBYP reduces both external noise and the noise generated by the chopper-stabilization function. As shown in figure 3, a 0.01 μF capacitor is typical. V+ VCC A114x Installation of CBYP must ensure that the traces that connect it to the A114x pins are no greater than 5 mm in length. All high-frequency interferences conducted along the supply lines are passed directly to the load through CBYP, and it serves only to protect the A114x internal circuitry. As a result, the load ECU (electronic control unit) must have sufficient protection, other than CBYP, installed in parallel with the A114x. GND CBYP 0.01 μF GND B A A series resistor on the supply side, RS (not shown), in combination with CBYP, creates a filter for EMI pulses. When determining the minimum VCC requirement of the A114x device, the voltage drops across RS and the ECU sense resistor, RSENSE, must be taken into consideration. The typical value for RSENSE is approximately 100 Ω. B A Package UA Only B Maximum separation 5 mm RSENSE ECU Figure 3. Typical application circuit For additional general application information, visit the Allegro Web site at www. allegromicro.com. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 9 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 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 Example: Reliability for VCC at TA = 150°C, package UA, using minimum-K PCB. Observe the worst-case ratings for the device, specifically: RθJA = 165°C/W, TJ(max) = 165°C, VCC(max) = 24 V, and ICC(max) = 17 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 ÷ 165 °C/W = 91 mW Finally, invert equation 1 with respect to voltage: VCC(est) = PD(max) ÷ ICC(max) = 91 mW ÷ 17 mA = 5 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. (3) For example, given common conditions such as: TA= 25°C, VCC = 12 V, ICC = 4 mA, and RθJA = 140 °C/W, then: PD = VCC × ICC = 12 V × 4 mA = 48 mW ΔT = PD × RθJA = 48 mW × 140 °C/W = 7°C TJ = TA + ΔT = 25°C + 7°C = 32°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. 10 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Device Qualification Program Contact Allegro for information. EMC (Electromagnetic Compatibility) Requirements Contact your local representative for EMC results. Test Name Reference Specification ESD – Human Body Model AEC-Q100-002 ESD – Machine Model AEC-Q100-003 Conducted Transients ISO 7637-2 Direct RF Injection ISO 11452-7 Bulk Current Injection ISO 11452-4 TEM Cell ISO 11452-3 11 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Package LH, 3-Pin; (SOT-23W) 3.00 .118 2.70 .106 0.15 [.006] M C A B 3.04 .120 2.80 .110 3 A A 1.49 .059 NOM B B 8º 0º 0.20 .008 0.08 .003 2.10 .083 1.85 .073 Preliminary dimensions, for reference only Dimensions in millimeters U.S. Customary dimensions (in.) in brackets, for reference only (reference JEDEC TO-236 AB, except case width and terminal tip-to-tip) Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Hall element (not to scale) B Active Area Depth 0.28 [.011] A 0.96 .038 0.60 .024 0.25 .010 A NOM 1 2 0.25 .010 3X SEATING PLANE 0.10 [.004] C 3X 0.50 .020 0.30 .012 C SEATING PLANE GAUGE PLANE 1.17 .046 0.75 .030 0.20 [.008] M C A B 0.15 .006 0.00 .000 0.95 .037 1.90 .075 12 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches A1140, A1141, A1142, and A1143 Package UA, 3-Pin SIP .164 4.17 .159 4.04 C D .0805 2.04 .062 1.57 .058 1.47 NOM .122 3.10 .117 2.97 D .0565 1.44 NOM D B .085 2.16 MAX .031 0.79 REF A .017 0.44 .014 0.35 .640 16.26 .600 15.24 1 2 3 .019 0.48 .014 0.36 .050 1.27 NOM Dimensions in inches Metric dimensions (mm) in brackets, for reference only A Dambar removal protrusion (6X) B Ejector mark on opposite side C Active Area Depth .0195 [0.50] NOM D Hall element (not to scale) 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, 2006 Allegro MicroSystems, Inc. 13 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com