Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch

A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch Features and Benefits ▪ ▪ ▪ ▪ ▪ 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 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. 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 Package: 8 pin SOIC (suffix L), and 4 pin SIP (suffix K) www.DataSheet4U.com Continued on the next page… Not to scale Typical Application VOUTPUTB VOUTPUTA 2 OUTPUTA VSupply 100 Ω 1 A3425 VCC OUTPUTB 3 GND 4 0.1 uF Using unregulated supply A3425DS-Rev. 6 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch 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. 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 Selection Guide Part Number A3425EK-T A3425EKTN-T A3425EL-T A3425ELTR-T A3425LK-T A3425LKTN-T A3425LL-T A3425LLTR-T 1Pb-based Pb-free1 Yes Yes Yes Yes Yes Yes Yes Yes Packing2 Bulk, 500 pieces/bag 13-in. reel, 4000 pieces/reel Bulk, 500 pieces/bag 13-in. reel, 3000 pieces/reel Bulk, 98 pieces/bag 13-in. reel, 4000 pieces/reel Bulk, 500 pieces/bag 13-in. reel, 3000 pieces/reel Mounting 4-pin SIP through hole Ambient, TA –40ºC to 85ºC 8-pin SOIC surface mount 4-pin SIP through hole –40ºC to 150ºC 8-pin SOIC surface mount 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. for additional packing options. 2Contact Allegro Absolute Maximum Ratings Characteristic Supply Voltage Reverse Battery Voltage Output Off Voltage Output Sink Current Magnetic Flux Density Operating Ambient Temperature Maximum Junction Temperature Storage Temperature Symbol VCC VRCC VOUTPUT IOUTPUT(Sink) B TA TJ(max) Tstg Range E Range L Notes Rating 26.5 –16 VCC Internally Limited Unlimited –40 to 85 –40 to 150 165 –65 to 170 Units V V V – – ºC ºC ºC ºC 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 Functional Block Diagram VCC Programmable Trim Regulator 8 Bits Channel A 4 Bits Dynamic Offset Cancellation Hall Element E1 Sample and Hold OUTPUTA LowPass Filter Output Drive Amp Channel B 4 Bits Dynamic Offset Cancellation Hall Element E2 Sample and Hold OUTPUTB LowPass Filter Output Drive Amp GND Terminal List Table Package K Package L 1 E1 E2 1 2 3 1 2 3 4 4 E1 8 7 6 5 Pin Number Package K Package L 1 2 3 4 5-8 Name VCC Function Connects power supply to on-chip voltage regulator 2 3 4 – OUTPUTA Output from E1 via first Schmitt circuit OUTPUTB Output from E2 via second Schmitt circuit GND NC Terminal for ground connection No connection E2 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 – – – – – – – – – – – <1 1.8 1.2 3.5 4.0 160 – – – 340 18 10 – – 6.0 6.0 500 20 70 220 – V μA μs μs mA mA mV mA mA mA kHz Symbol Test Conditions Min. Typ. Max Units Output Sink Current, Peak3 Chopping Frequency TRANSIENT PROTECTION CHARACTERISTICS Supply Zener Voltage Supply Zener Current4 Reverse-Battery Current VZ IZ IRCC ICC = 15 mA VS = 28 V VRCC = –18 V, TJ < TJ(max) 28 – – 33 – 2 37 9.0 15 V mA mA Continued on the next page... Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 4 A3425 Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch 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 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) 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. 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 Package Thermal Resistance Symbol RθJA Test Conditions* Package K, 1-layer PCB with copper limited to solder pads Package L-8 pin, 1-layer PCB with copper limited to solder pads Package L-8 pin, 4-layer PCB based on JEDEC standard *Additional thermal data available on the Allegro Web site. Value Units 177 140 80 ºC/W ºC/W ºC/W Power Derating Curve 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 20 40 Maximum Allowable VCC (V) 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) 60 80 100 120 140 160 180 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) P (R ack ag θJ A = e 80 L, 4 ºC -la /W ye Pa cka ) rP (R ge C θJA B L, =1 1-l 40 aye ºC rP /W CB Pac ) (R kage K θJA = , 1la 177 ºC/ yer PC W) B 60 80 100 120 140 Temperature, TA (°C) 160 180 Allegro MicroSystems, Inc