A3425

A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch The A3425 is a dual-output channel, bipolar switch with two separate Hall-effect sensor circuits, each providing a separate digital output for speed and direction signal processing capability. Each sensor circuit has its own independent Hall element, which are photolithographically aligned to better than 1 µm. Maintaining accurate mechanical location between the two active Hall elements eliminates the major manufacturing hurdle encountered in fine-pitch detection applications. The A3425 is a highly sensitive, temperature-stable magnetic sensing device, which is ideal for use in ring magnet-based speed and direction systems used in harsh automotive and industrial environments. The A3425 monolithic integrated circuit contains two independent Hall effect switches, located approximately 1 mm apart. The digital outputs are 90º out of phase so that the outputs are in quadrature with the proper ring magnet design. This allows for easy processing of speed and direction signals. Extremely lowdrift amplifiers guarantee symmetry between the switches to maintain signal quadrature. The patented chopper stabilization technique cancels offsets in each channel, and provides stable operation over the operating temperature and voltage ranges. An on-chip regulator allows the use of this device over a wide operating voltage range. Post-assembly factory programming provides sensitive switchpoints that are symmetrical between the two switches. The A3425 is available in a plastic 8-pin SOIC surface mount package and a plastic 4-pin SIP, both in two temperature ranges. Each package is available in a lead (Pb) free version with 100% matte tin plated leadframe. Package L, 8-pin SOIC VCC OUTPUTA OUTPUTB GND 1 2 3 4 8 7 6 5 No connection No connection No connection No connection Package K, 4-pin SIP 1. VCC 2. OUTPUTA 3. OUTPUTB 4. GND 1 2 3 4 ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC ....................................... 26.5 V Reverse-Battery Voltage, VRCC........................ –18 V Output Off Voltage, VOUTPUT ..............................VCC Output Sink Current, IOUTPUT(SINK) . Internally Limited Magnetic Flux Density, B .......................... Unlimited Operating Temperature Ambient, TA, Range E.................. –40ºC to 85ºC Range L................ –40ºC to 150ºC Maximum Junction, TJ(max)........................165ºC Storage Temperature, TS .................. –65ºC to 170ºC Features and Benefits • Two matched Hall effect switches on a single substrate • • • • • • • Sensor element spacing approximately 1 mm Superior temperature stability 3.3 V to 18 V operation Integrated ESD diode from OUTPUT and VCC pins to GND High-sensitivity switchpoints Robust structure for EMC protection Solid-state reliability A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Functional Block Diagram VCC Programmable Trim Regulator 8 Bits 4 Bits Sample and Hold Dynamic Offset Cancellation OUTPUTA LowPass Filter Output Drive Amp 4 Bits Sample and Hold Dynamic Offset Cancellation OUTPUTB LowPass Filter Output Drive Amp GND Terminal List Symbol VCC OUTPUTA OUTPUTB GND – Description Connects power supply to on-chip voltage regulator Output from first Schmitt circuit Output from second Schmitt circuit Ground No connection Package K 1 2 3 4 – L 1 2 3 4 5, 6, 7, 8 A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Product Selection Guide Part Number A3425EK A3425EK-T A3425EKTN A3425EKTN-T A3425EL A3425EL-T A3425ELTR A3425ELTR-T A3425LK A3425LK-T A3425LKTN A3425LKTN-T A3425LL A3425LL-T A3425LLTR A3425LLTR-T Pb-free – Yes – Yes – Yes – Yes – Yes – Yes – Yes – Yes Packing* Bulk, 98 pieces/bag Bulk, 98 pieces/bag 13-in. reel, 4000 pieces/reel 13-in. reel, 4000 pieces/reel Bulk, 500 pieces/bag Bulk, 500 pieces/bag 13-in. reel, 3000 pieces/reel 13-in. reel, 3000 pieces/reel Bulk, 98 pieces/bag Bulk, 98 pieces/bag 13-in. reel, 4000 pieces/reel 13-in. reel, 4000 pieces/reel Bulk, 500 pieces/bag Bulk, 500 pieces/bag 13-in. reel, 3000 pieces/reel 13-in. reel, 3000 pieces/reel 8-pin SOIC surface mount 4-pin SIP through hole –40ºC to 150ºC 8-pin SOIC surface mount 4-pin SIP through hole –40ºC to 85ºC Mounting Ambient, TA *Contact Allegro for additional packing options. A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch OPERATING CHARACTERISTICS Valid over operating temperature ranges unless otherwise noted; typical data applies to VCC = 12 V, and TA = 25ºC Characteristic ELECTRICAL CHARACTERISTICS Supply Voltage1 Output Leakage Current Output Rise Time Output Fall Time Supply Current Low Output Voltage Output Sink Current Output Sink Current, Continuous2 VCC IOUTPUT(OFF) tr tf ICC(OFF) ICC(ON) VOUTPUT(ON) IOUTPUT(SINK) IOUTPUT(SINK)C IOUTPUT(SINK)P fC TJ < TJ(max) ,VOUTPUT = 12 V t < 3 seconds Operating; TA ≤ 150°C Either output CLOAD = 20 pF, RLOAD = 820 Ω CLOAD = 20 pF, RLOAD = 820 Ω B < BRP(A) ,B < BRP(B) B > BOP(A) ,B > BOP(B) Both outputs; IOUTPUT(SINK) = 20 mA; B > BOP(A), B > BOP(B) 3.3 – – – – – – – – – – – BOP Release Point: B < BRP Hysteresis: BOP(A) – BRP(A), BOP(B) – BRP(B) Symmetry: Channel A, Channel B, BOP(A) + BRP(A), BOP(B) + BRP(B) Operate Symmetry: BOP(A) – BOP(B) Release Symmetry: BRP(A) – BRP(B) Symbol Package5 BOP(A), BOP(B) BRP(A), BRP(B) BHYS(A), BHYS(B) SYMA, SYMB SYMAB(OP) SYMAB(RP) – –35 5 –40 –30 –30 7 –7 16 – – – 35 – 40 40 30 30 G G G G G G Test Conditions Min. Typ. Max Units MAGNETIC CHARACTERISTICS, L Package5 Operate Point: B > BOP Release Point: B < BRP Hysteresis: BOP(A) – BRP(A), BOP(B) – BRP(B) Symmetry: Channel A, Channel B, BOP(A) + BRP(A), BOP(B) + BRP(B) Operate Symmetry: BOP(A) – BOP(B) Release Symmetry: BRP(A) – BRP(B) 1 2 BOP(A), BOP(B) BRP(A), BRP(B) BHYS(A), BHYS(B) SYMA, SYMB SYMAB(OP) SYMAB(RP) – –30 5 –35 –25 –25 7 –7 14 – – – 30 – 35 35 25 25 G G G G G G When operating at maximum voltage, never exceed maximum junction temperature, TJ(max). Refer to power derating curve charts. Device will survive the current level specified, but operation within magnetic specification cannot be guaranteed. 3 Short circuit of the output to VCC is protected for the time duration specified. 4 Maximum specification limit is equivalent to I CC(max) + 3 mA. 5 Magnetic flux density, B, is indicated as a negative value for north-polarity magnetic fields, and as a positive value for south-polarity magnetic fields. This so-called algebraic convention supports arithmetic comparison of north and south polarity values, where the relative strength of the field is indicated by the absolute value of B, and the sign indicates the polarity of the field (for example, a –100 G field and a 100 G field have equivalent strength, but opposite polarity). EMC Contact Allegro MicroSystems for EMC performance. A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 5 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions Value Units Package K, minimum-K PCB (single-sided with copper limited to 177 ºC/W solder pads) Package L, minimum-K PCB (single-sided with copper limited to 140 ºC/W solder pads) Package L, high-K PCB (multilayer with significant copper 80 ºC/W areas, based on JEDEC standard) Package Thermal Resistance RθJA Power Derating Curve TJ(max) = 165ºC; ICC = ICC(max) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 20 VCC(max) High-K PCB, Package L (RθJA = 80 ºC/W) Minimum-K PCB, Package L (RθJA = 140 ºC/W) Minimum-K PCB, Package K (RθJA = 177 ºC/W) VCC(min) 40 60 80 100 120 140 160 180 Maximum Allowable VCC (V) Temperature (ºC) Power Dissipation versus Temperature 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 20 40 Power Dissipation, PD (m W) H (R igh θJ A Min (R imum e θJA L = 1 -K P 40 CB ºC , Pa /W cka Min ) ge (R imumL KP θJA = 177 CB, Pac ºC/ W) kag eK -K = PC 80 B, ºC Pa /W ck ) ag 60 80 100 120 140 Temperature, TA (°C) 160 180 A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 6 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Functional Description Chopper-Stabilized 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 device. This makes it difficult to process the signal and maintain an accurate, reliable output over the specified temperature and voltage range. Chopper stabilization is a unique approach used to minimize Hall offset on the chip. The patented Allegro technique, dynamic quadrature offset cancellation, removes key sources of the output drift induced by thermal and mechanical stress. This offset reduction technique is based on a signal modulationdemodulation process. The undesired offset signal is separated from the magnetically induced signal in the frequency domain through modulation. The subsequent demodulation acts as a modulation process for the offset, causing the magnetically-induced signal to recover its original spectrum at the baseband level, while the dc offset becomes a high-frequency signal. Then, using a low-pass filter, the signal passes while the modulated dc offset is suppressed. The chopper stabilization technique uses a 170 kHz high-frequency clock. The Hall element chopping occurs on each clock edge, resulting in a 340 kHz chop frequency. This high-frequency operation allows for a greater sampling rate, which produces higher accuracy and faster signal processing capability. This approach desensitizes the chip to the effects of thermal and mechanical stress. The disadvantage to this approach is that jitter, also known as 360° repeatability, can be induced on the output signal. The sample-andhold process, used by the demodulator to store and recover the signal, can slightly degrade the signal-tonoise ratio. This is because the process generates replicas of the noise spectrum at the baseband, causing a decrease in jitter performance. However, the improvement in switchpoint performance, resulting from the reduction of the effects of thermal and mechanical stress, outweighs the degradation in the signal-to-noise ratio. This technique produces devices that have an extremely stable quiescent Hall element output voltage, are immune to thermal stress, and have precise recoverability after temperature cycling. This technique is made possible through the use of a BiCMOS process, which allows the use of low-offset and low-noise amplifiers in combination with high-density logic integration and sample-and-hold circuits. This process is illustrated in the following diagram. Regulator Sample and Hold Amp LowPass Filter Chopper stabilization circuit (dynamic quadrature offset cancellation) A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 7 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Typical Applications Operation V+ Switch to High Switch to Low VOUTPUT(OFF) VOUTPUT VOUTPUT(ON)(sat) BRP B+ BOP BHYS Output voltage in relation to sensed magnetic flux density. Output on each channel independently follows the same pattern of transition through BOP followed by transition through BRP. M agnetic Field Sensor A M agnetic Field Sensor B Output Sensor A Output Sensor B Quadrature output signal configuration. The outputs of the two output channels have a phase difference of 90º when used with a properly designed magnet that has an optimal pole pitch of twice the Hall element spacing of 1.0 mm. A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 8 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Typical Applications Circuits This device requires minimal protection circuitry during operation with a low-voltage regulated line. The on-chip voltage regulator provides immunity to power supply variations between 3.3 and 18 V. Because the device has open-collector outputs, pullup resistors must be included. If protection against coupled and injected noise is required, then a simple low-pass filter on the supply (RC) and a filtering capacitor on each of the outputs may also be needed, as shown in the unregulated supply diagram. For applications in which the device receives its power from unregulated sources, such as a car battery, full protection is generally required to protect the device against supply-side transients. Specifications for such transients vary for each application, so the design of the protection circuit should be optimized for each application. For example, the circuit shown in the unregulated supply diagram includes a Zener diode that offers high voltage load-dump protection and noise filtering by means of a series resistor and capacitor. In addition, it includes a series diode that protects against high-voltage reverse battery conditions. VOUTPUTB VOUTPUTA 2 OUTPUTA VSupply 1 A3425 VCC OUTPUTB 3 GND 0.1 uF 4 Regulated supply VOUTPUTB VOUTPUTA 2 OUTPUTA VSupply 100 Ω 1 A3425 VCC OUTPUTB 3 GND 4 0.1 uF Unregulated supply A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 9 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Typical Thermal Performance 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 ∆T = PD × RθJA TJ = TA + ∆T (1) (2) (3) Example: Reliability for VCC at TA = 150°C, package L, using minimum-K PCB Observe the worst-case ratings for the device, specifically: RθJA = 140 °C/W, TJ(max) = 165°C, VCC(max) = 18 V, and ICC(max) = 6 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 ÷ 140 °C/W = 107 mW Finally, invert equation 1 with respect to voltage: VCC(est) = PD(max) ÷ ICC(max) = 107 mW ÷ 6 mA = 18 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 mA, and RθJA = 140 °C/W, then: PD = VCC × ICC = 12 V × 4 mA = 48 mW ∆T = PD × RθJA = 48 mW × 140 °C/W = 7°C TJ = TA + ∆T = 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. A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 10 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Electrical Operating Characteristics, Package L ICC(off) 8 7 6 Current (mA) 5 4 3 2 1 0 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C Current (mA) 8 7 6 5 4 3 2 1 0 -50 0 50 100 150 200 Temperature (°C) 3.3 V 18 V ICC(off) ICC(on) 8 7 6 Current (mA) -40°C 25°C 150°C Current (mA) 5 4 3 2 1 0 0 5 10 VCC (V) 15 20 8 7 6 5 4 3 2 1 0 -50 0 50 ICC(on) 3.3 V 18 V 100 150 200 Temperature (°C) Output Saturation Voltage VCC = 3.3 V, Isink = 20 mA 500 400 Vsat (mV) 300 200 100 0 -50 0 50 100 150 200 Ch. A Ch. B Temperature (°C) A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 11 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Magnetic Operating Characteristics, Package L Channel A, BOP and BRP 30 20 Switchpoint (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 BOP BRP -40°C 25°C 150°C 30 20 Switchpoint (G) 10 0 -10 -20 -30 -50 0 50 100 150 200 BOP BRP Channel A, BOP and BRP 3.3 V 12 V 18 V Temperature (°C) Channel B, BOP and BRP 30 20 Switchpoint (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 BOP BRP -40°C 25°C 150°C 30 20 Switchpoint (G) 10 0 -10 -20 -30 -50 0 Channel B, BOP and BRP BOP BRP 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) Channels A and B, Hysteresis 30 25 BOP - BRP (G) BOP - BRP (G) 20 15 10 5 0 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C 30 25 20 15 10 5 0 -50 Channels A and B, Hysteresis 3.3 V 12 V 18 V 0 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 12 A3425DS-Rev. ! A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Magnetic Operating Characteristics, Package L (continued) BOP Symmetry 30 20 Ch. A - Ch. B (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 Ch. A - Ch. B (G) -40°C 25°C 150°C 30 20 10 0 -10 -20 -30 -50 0 BOP Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) BRP Symmetry 30 20 Ch. A - Ch. B (G) Ch. A - Ch. B (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C 30 20 10 0 -10 -20 -30 -50 0 BRP Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 13 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Magnetic Operating Characteristics, Package L (continued) Ch. A Symmetry 30 20 BOP + BRP (G) -40°C 25°C 150°C BOP + BRP (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 30 20 10 0 -10 -20 -30 -50 0 Ch. A Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) Ch. B Symmetry 30 20 BOP + BRP (G) BOP + BRP (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C 30 20 10 0 -10 -20 -30 -50 0 Ch. B Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 14 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Electrical Operating Characteristics, Package K ICC(off) 8 7 6 Current (mA) 5 4 3 2 1 0 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C Current (mA) 8 7 6 5 4 3 2 1 0 -50 0 50 100 150 200 Temperature (°C) 3.3 V 18 V ICC(off) ICC(on) 8 7 6 Current (mA) -40°C 25°C 150°C Current (mA) 5 4 3 2 1 0 0 5 10 VCC (V) 15 20 8 7 6 5 4 3 2 1 0 -50 0 50 ICC(on) 3.3 V 18 V 100 150 200 Temperature (°C) Output Saturation Voltage VCC = 3.3 V, Isink = 20 mA 500 400 Vsat (mV) 300 200 100 0 -50 0 50 100 150 200 Ch. A Ch. B Temperature (°C) A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 15 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Magnetic Operating Characteristics, Package K Channel A, BOP and BRP 30 20 Switchpoint (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 BOP BRP -40°C 25°C 150°C 30 20 Switchpoint (G) 10 0 -10 -20 -30 -50 0 50 100 150 200 BOP BRP Channel A, BOP and BRP 3.3 V 12 V 18 V Temperature (°C) Channel B, BOP and BRP 30 20 Switchpoint (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 BOP BRP -40°C 25°C 150°C 30 20 Switchpoint (G) 10 0 -10 -20 -30 -50 0 Channel B, BOP and BRP BOP BRP 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) Channels A and B, Hysteresis 30 25 BOP - BRP (G) BOP - BRP (G) 20 15 10 5 0 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C 30 25 20 15 10 5 0 -50 Channels A and B, Hysteresis 3.3 V 12 V 18 V 0 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 16 A3425DS-Rev. ! A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Magnetic Operating Characteristics, Package K (continued) BOP Symmetry 30 20 Ch. A - Ch. B (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 Ch. A - Ch. B (G) -40°C 25°C 150°C 30 20 10 0 -10 -20 -30 -50 0 BOP Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) BRP Symmetry 30 20 Ch. A - Ch. B (G) Ch. A - Ch. B (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C 30 20 10 0 -10 -20 -30 -50 0 BRP Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 17 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Magnetic Operating Characteristics, Package K (continued) Ch. A Symmetry 30 20 BOP + BRP (G) -40°C 25°C 150°C BOP + BRP (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 30 20 10 0 -10 -20 -30 -50 0 Ch. A Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) Ch. B Symmetry 30 20 BOP + BRP (G) BOP + BRP (G) 10 0 -10 -20 -30 0 5 10 VCC (V) 15 20 -40°C 25°C 150°C 30 20 10 0 -10 -20 -30 -50 0 Ch. B Symmetry 3.3 V 12 V 18 V 50 100 150 200 Temperature (°C) A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 18 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Package K, 4-pin SIP A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 19 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Package L, 8-pin SOIC A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 20 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch 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 © 2005, Allegro MicroSystems, Inc. A3425DS-Rev. ! Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 21