A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Features and Benefits Description ▪ ▪ ▪ ▪ ▪ The A3425 is a dual–output-channel, bipolar switch with each channel comprising a separate complete Hall-effect sensor circuit with dedicated Hall element and separate digital output for speed and direction signal processing capability. The independent Hall elements (E1 integrated with OUTPUTA, and E2 integrated with OUTPUTB) are photolithographically aligned to better than 1 μm. Maintaining this 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 magnetbased speed and direction systems used in harsh automotive and industrial environments. Two matched Hall effect switches on a single substrate Sensor Hall element spacing approximately 1 mm Superior temperature stability 3.3 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 Package: 8 pin SOIC (suffix L), and 4 pin SIP (suffix K) The A3425 contains two independent Hall effect switches, and has a monolithic IC that accurately locates the two Hall elements, E1 and E2, 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 low-drift amplifiers guarantee symmetry between the switches to maintain signal Continued on the next page… Not to scale Typical Application VOUTPUTB VOUTPUTA 2 OUTPUTA VSupply 1 A3425 VCC OUTPUTB 100 Ω GND 4 0.1 uF Using unregulated supply A3425DS-Rev. 6 3 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Description (continued) 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 (L) and a plastic 4-pin SIP (K), both in two operating temperature ranges. Each package is available in a lead (Pb) free version with 100% matte tin plated leadframe. Selection Guide Part Number Pb-free1 Packing2 A3425EK-T Yes Bulk, 500 pieces/bag A3425EKTN-T Yes 13-in. reel, 4000 pieces/reel A3425EL-T Yes Bulk, 500 pieces/bag A3425ELTR-T Yes 13-in. reel, 3000 pieces/reel A3425LK-T Yes Bulk, 98 pieces/bag A3425LKTN-T Yes 13-in. reel, 4000 pieces/reel A3425LL-T Yes Bulk, 500 pieces/bag A3425LLTR-T Yes 13-in. reel, 3000 pieces/reel Mounting Ambient, TA 4-pin SIP through hole –40ºC to 85ºC 8-pin SOIC surface mount 4-pin SIP through hole –40ºC to 150ºC 8-pin SOIC surface mount 1Pb-based variants are being phased out of the product line. The 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 variants 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: A3425EL, A3425ELTR, A3425LL, and A3425LLTR. 2Contact Allegro for additional packing options. Absolute Maximum Ratings Characteristic Symbol Notes Rating Units Supply Voltage VCC 26.5 V Reverse Battery Voltage VRCC –16 V V Output Off Voltage VOUTPUT VCC IOUTPUT(Sink) Internally Limited – Magnetic Flux Density B Unlimited – Operating Ambient Temperature TA Maximum Junction Temperature Output Sink Current Storage Temperature Range E –40 to 85 ºC Range L –40 to 150 ºC TJ(max) 165 ºC Tstg –65 to 170 ºC Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Functional Block Diagram VCC Programmable Trim Regulator 8 Bits Channel A Amp OUTPUTA Sample and Hold Dynamic Offset Cancellation 4 Bits Hall Element E1 LowPass Filter Output Drive Channel B Amp OUTPUTB Sample and Hold Hall Element E2 Dynamic Offset Cancellation 4 Bits LowPass Filter Output Drive GND Terminal List Table Package K E1 Package L 1 E2 2 3 1 2 3 4 4 E1 E2 8 7 6 5 Pin Number Name Function Package K Package L 1 1 2 2 OUTPUTA Output from E1 via first Schmitt circuit 3 3 OUTPUTB Output from E2 via second Schmitt circuit 4 4 GND – 5-8 NC VCC Connects power supply to on-chip voltage regulator Terminal for ground connection No connection Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 OPERATING CHARACTERISTICS Valid over operating temperature ranges unless otherwise noted; typical data applies to VCC = 12 V, and TA = 25ºC Characteristic Symbol Test Conditions Min. Typ. Max Units ELECTRICAL CHARACTERISTICS Supply Voltage1 VCC Output Leakage Current IOUTPUT(OFF) Operating; TA ≤ 150°C 3.3 – 18 V Either output – <1 10 μA Output Rise Time tr CLOAD = 20 pF, RLOAD = 820 Ω – 1.8 – μs Output Fall Time tf CLOAD = 20 pF, RLOAD = 820 Ω – 1.2 – μs ICC(OFF) B < BRP(A) ,B < BRP(B) – 3.5 6.0 mA ICC(ON) B > BOP(A) ,B > BOP(B) – 4.0 6.0 mA Both outputs; IOUTPUT(SINK) = 20 mA; B > BOP(A), B > BOP(B) – 160 500 mV – – 20 mA Supply Current Low Output Voltage VOUTPUT(ON) Output Sink Current Output Sink Current, IOUTPUT(SINK) Continuous2 Output Sink Current, Peak3 Chopping Frequency IOUTPUT(SINK)C TJ < TJ(max) ,VOUTPUT = 12 V – – 70 mA IOUTPUT(SINK)P t < 3 seconds – – 220 mA – 340 – kHz fC TRANSIENT PROTECTION CHARACTERISTICS Supply Zener Voltage VZ ICC = 15 mA 28 33 37 V Supply Zener Current4 IZ VS = 28 V – – 9.0 mA VRCC = –18 V, TJ < TJ(max) – 2 15 mA Reverse-Battery Current IRCC Continued on the next page... Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 4 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 OPERATING CHARACTERISTICS (continued) Valid over operating temperature ranges unless otherwise noted; typical data applies to VCC = 12 V, and TA = 25ºC Characteristic MAGNETIC CHARACTERISTICS, K Symbol Test Conditions Min. Typ. Max Units Package5 Operate Point: B > BOP BOP(A), BOP(B) – 7 35 G Release Point: B < BRP BRP(A), BRP(B) –35 –7 – G BHYS(A), BHYS(B) 5 16 40 G SYMA, SYMB –40 – 40 G Operate Symmetry: BOP(A) – BOP(B) SYMAB(OP) –30 – 30 G Release Symmetry: BRP(A) – BRP(B) SYMAB(RP) –30 – 30 G Hysteresis: BOP(A) – BRP(A), BOP(B) – BRP(B) Symmetry: Channel A, Channel B, BOP(A) + BRP(A), BOP(B) + BRP(B) MAGNETIC CHARACTERISTICS, L Package5 Operate Point: B > BOP BOP(A), BOP(B) – 7 30 G Release Point: B < BRP BRP(A), BRP(B) –30 –7 – G BHYS(A), BHYS(B) 5 14 35 G SYMA, SYMB –35 – 35 G Operate Symmetry: BOP(A) – BOP(B) SYMAB(OP) –25 – 25 G Release Symmetry: BRP(A) – BRP(B) SYMAB(RP) –25 – 25 G Hysteresis: BOP(A) – BRP(A), BOP(B) – BRP(B) Symmetry: Channel A, Channel B, BOP(A) + BRP(A), BOP(B) + BRP(B) 1 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). 2 EMC Contact Allegro MicroSystems for EMC performance. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 5 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions* RθJA Package Thermal Resistance Value Units Package K, 1-layer PCB with copper limited to solder pads 177 ºC/W Package L-8 pin, 1-layer PCB with copper limited to solder pads 140 ºC/W Package L-8 pin, 4-layer PCB based on JEDEC standard 80 ºC/W *Additional thermal data available on the Allegro Web site. Maximum Allowable VCC (V) Power Derating Curve 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 VCC(max) Package L, 4-layer PCB (RθJA = 80 ºC/W) Package L, 1-layer PCB (RθJA = 140 ºC/W) Package K, 1-layer PCB (RθJA = 177 ºC/W) VCC(min) 20 40 60 80 100 120 140 160 180 Temperature (ºC) Power Dissipation, PD (m W) Power Dissipation versus Temperature 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 P (R ack ag θJ A = e 80 L, 4 ºC -la /W ye Pa cka ) rP (R ge C θJA B L = 1 , 1lay 40 ºC er P /W CB Pac ) (R kage K θJA = , 1la 177 ºC/ yer PC W) B 20 40 60 80 100 120 140 Temperature, TA (°C) 160 180 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 6 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 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 modulation-demodulation 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 signalto-noise 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 lownoise amplifiers in combination with high-density logic integration and sample-and-hold circuits. This process is illustrated in the following diagram. Amp Sample and Hold Regulator LowPass Filter 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 7 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Typical Applications Operation Switch to High VOUTPUT(OFF) Switch to Low VOUTPUT V+ VOUTPUT(ON)(sat) BRP BOP B+ 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. Channel A M agnetic Field at Hall Element E1 Channel B M agnetic Field at Hall Element E2 Channel A Output Signal at OUTPUTA Channel B Output Signal at OUTPUTB 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. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 8 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 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-drain outputs, pull-up resistors must be included. 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. 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 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 1 A3425 VCC OUTPUTB 3 100 Ω GND 4 0.1 uF Unregulated supply Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 9 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 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 (1) ΔT = PD × RθJA (2) TJ = TA + ΔT (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: 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 ÷ 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 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 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Electrical Operating Characteristics, Package L ICC(off) 8 8 7 7 6 6 5 -40°C 4 25°C 3 150°C 2 Current (mA) Current (mA) ICC(off) 1 3.3 V 18 V 5 4 3 2 1 0 0 0 5 10 15 -50 20 0 50 ICC(on) 150 200 ICC(on) 8 7 7 6 6 5 -40°C 4 25°C 3 150°C 2 Current (mA) 8 1 5 3.3 V 4 18 V 3 2 1 0 0 5 10 15 0 20 -50 0 50 100 150 200 Temperature (°C) VCC (V) Output Saturation Voltage VCC = 3.3 V, Isink = 20 mA 500 400 Vsat (mV) Current (mA) 100 Temperature (°C) VCC (V) Ch. A 300 Ch. B 200 100 0 -50 0 50 100 150 200 Temperature (°C) 11 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Magnetic Operating Characteristics, Package L Channel A, BOP and BRP Channel A, BOP and BRP 30 30 20 BOP 10 0 -40°C 25°C 150°C BRP -10 -20 -30 0 5 10 15 Switchpoint (G) Switchpoint (G) 20 0 0 100 150 200 Channel B, BOP and BRP 30 20 BOP 10 0 -40°C 25°C 150°C BRP -10 Switchpoint (G) 20 Switchpoint (G) 50 Temperature (°C) 30 -20 0 5 10 15 0 3.3 V 12 V 18 V BRP -10 -20 -30 -50 20 BOP 10 0 50 100 150 200 Temperature (°C) VCC (V) Channels A and B, Hysteresis Channels A and B, Hysteresis 30 30 25 25 20 -40°C 25°C 150°C 15 10 BOP - BRP (G) BOP - BRP (G) 18 V -20 Channel B, BOP and BRP 20 3.3 V 12 V 18 V 15 10 5 5 0 12 V BRP VCC (V) -30 3.3 V -10 -30 -50 20 BOP 10 0 5 10 15 VCC (V) 20 0 -50 0 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page 12 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Magnetic Operating Characteristics, Package L (continued) BOP Symmetry BOP Symmetry 30 30 20 10 -40°C 0 25°C 150°C -10 -20 -30 0 5 10 15 Ch. A - Ch. B (G) Ch. A - Ch. B (G) 20 12 V 0 18 V -10 -20 -30 -50 20 3.3 V 10 0 VCC (V) 20 20 10 -40°C 0 25°C 150°C -10 -20 10 15 VCC (V) 20 Ch. A - Ch. B (G) Ch. A - Ch. B (G) 30 5 150 200 BRP Symmetry BRP Symmetry 0 100 Temperature (°C) 30 -30 50 10 3.3 V 0 12 V -10 18 V -20 -30 -50 0 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page 13 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Magnetic Operating Characteristics, Package L (continued) Channel A Symmetry 30 30 20 20 10 -40°C 0 25°C 150°C -10 -20 BOP + BRP (G) BOP + BRP (G) Channel A Symmetry -30 0 5 10 15 10 12 V -10 18 V -20 -30 -50 20 3.3 V 0 0 VCC (V) 20 20 10 10 -40°C 0 25°C -10 150°C -20 -30 VCC (V) 15 20 BOP + BRP (G) BOP + BRP (G) 30 10 150 200 Channel B Symmetry 30 5 100 Temperature (°C) Channel B Symmetry 0 50 3.3 V 0 12 V -10 18 V -20 -30 -50 0 50 100 150 200 Temperature (°C) 14 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Electrical Operating Characteristics, Package K ICC(off) 8 8 7 7 6 6 5 -40°C 4 25°C 3 150°C 2 Current (mA) Current (mA) ICC(off) 1 3.3 V 18 V 5 4 3 2 1 0 0 0 5 10 15 -50 20 0 50 150 200 Temperature (°C) VCC (V) ICC(on) ICC(on) 8 7 7 6 6 5 -40°C 4 25°C 3 150°C 2 Current (mA) 8 1 5 3.3 V 4 18 V 3 2 1 0 0 5 10 15 0 20 -50 0 50 100 150 200 Temperature (°C) VCC (V) Output Saturation Voltage VCC = 3.3 V, Isink = 20 mA 500 400 Vsat (mV) Current (mA) 100 Ch. A 300 Ch. B 200 100 0 -50 0 50 100 150 200 Temperature (°C) 15 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Magnetic Operating Characteristics, Package K Channel A, BOP and BRP Channel A, BOP and BRP 30 30 20 BOP 10 0 -40°C 25°C 150°C BRP -10 -20 -30 0 5 10 15 Switchpoint (G) Switchpoint (G) 20 0 0 100 150 200 Channel B, BOP and BRP 30 20 BOP 10 0 -40°C 25°C 150°C BRP -10 Switchpoint (G) 20 Switchpoint (G) 50 Temperature (°C) 30 -20 0 5 10 15 0 3.3 V 12 V 18 V BRP -10 -20 -30 -50 20 BOP 10 0 50 100 150 200 Temperature (°C) VCC (V) Channels A and B, Hysteresis Channels A and B, Hysteresis 30 30 25 25 20 -40°C 25°C 150°C 15 10 BOP - BRP (G) BOP - BRP (G) 18 V -20 Channel B, BOP and BRP 20 3.3 V 12 V 18 V 15 10 5 5 0 12 V BRP VCC (V) -30 3.3 V -10 -30 -50 20 BOP 10 0 5 10 15 VCC (V) 20 0 -50 0 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page 16 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Magnetic Operating Characteristics, Package K (continued) BOP Symmetry BOP Symmetry 30 30 20 10 -40°C 0 25°C 150°C -10 -20 -30 0 5 10 15 Ch. A - Ch. B (G) Ch. A - Ch. B (G) 20 12 V 0 18 V -10 -20 -30 -50 20 3.3 V 10 0 VCC (V) 20 20 10 -40°C 0 25°C 150°C -10 -20 10 15 VCC (V) 20 Ch. A - Ch. B (G) Ch. A - Ch. B (G) 30 5 150 200 BRP Symmetry BRP Symmetry 0 100 Temperature (°C) 30 -30 50 10 3.3 V 0 12 V -10 18 V -20 -30 -50 0 50 100 150 200 Temperature (°C) Additional magnetic characteristics on next page 17 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Magnetic Operating Characteristics, Package K (continued) Channel A Symmetry 30 30 20 20 10 -40°C 0 25°C 150°C -10 -20 BOP + BRP (G) BOP + BRP (G) Channel A Symmetry -30 0 5 10 15 10 12 V -10 18 V -20 -30 -50 20 3.3 V 0 0 VCC (V) 30 30 20 20 10 -40°C 0 25°C -10 150°C -20 -30 5 10 VCC (V) 100 150 200 Channel B Symmetry 15 20 BOP + BRP (G) BOP + BRP (G) Channel B Symmetry 0 50 Temperature (°C) 10 3.3 V 0 12 V -10 18 V -20 -30 -50 0 50 100 150 200 Temperature (°C) 18 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Package K, 4-pin SIP .208 5.28 .203 5.16 D .138 3.51 .133 3.38 .0394 1.00 NOM .0828 2.10 D NOM C .063 1.60 .059 1.50 .0520 1.32 NOM B D E1 E2 A .045 1.14 MIN .033 0.84 NOM .021 0.53 MAX .085 2.16 MAX .600 15.24 .560 14.22 .017 0.44 .014 0.35 1 .019 .014 0.48 0.36 2 3 4 .050 1.27 NOM Dimensions in inches Millimeters in brackets, for reference only Case dimensions exclusive of mold flash or gate burrs Mold flash .010 [0.25] MAX, gate burr .008 [0.20] MAX, dambar protrusion .004 [0.10] MAX Exact case and lead configuration at supplier discretion within limits shown A Dambar removal protrusion (8X) B Ejector mark on opposite side C Active Area Depth .0165 [0.42] NOM D Hall elements E1, E2 (not to scale) 19 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch A3425 Package L, 8-pin SOIC 6.20 .244 5.80 .228 0.25 [.010] M B M 5.00 .197 4.80 .189 D 1.96 A .077 NOM D 1.00 8º 0º .039 NOM B 8 C 0.25 .010 0.17 .007 D 1.96 .077 E2 E1 NOM 4.00 .157 3.80 .150 1.27 .050 0.40 .016 A 1 D 2 1.40 .055 NOM 0.25 .010 8X 8X 0.51 .020 0.31 .012 1.75 .069 1.35 .053 0.25 [.010] M C A B 0.25 .010 0.10 .004 1.27 .050 Preliminary dimensions, for reference only Dimensions in millimeters U.S. Customary dimensions (in.) in brackets, for reference only (reference JEDEC MS-012 AA) Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown 2.50 .098 REF A Terminal #1 mark area B B 0.65 .026 MAX SEATING PLANE GAUGE PLANE C SEATING PLANE 0.10 [.004] C 4.90 .193 REF Reference pad layout (reference IPC SOIC127P600-8M); adjust as necessary to meet application process requirements C Active Area Depth 0.40 [0.016] D Hall elements E1, E2 (not to scale), U.S. Customary dimensions controlling 1.27 .050 REF 20 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 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, 2006, Allegro MicroSystems, Inc. 21 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com