Chopper-Stabilized Hall-Effect Bipolar Switch

A3230 Chopper-Stabilized Hall-Effect Bipolar Switch Features and Benefits ▪ Chopper stabilization ▫ Superior temperature stability ▫ Extremely low switchpoint drift ▫ Insensitive to physical stress ▪ Reverse battery protection ▪ Output short circuit protection ▪ Solid state reliability ▪ Small size ▪ Robust EMC capability ▪ High ESD ratings (HBM) Description The A3230 Hall-effect sensor is a temperature stable, stressresistant bipolar switch. This sensor is the most sensitive Hall-effect device in the Allegro® bipolar switch family and is intended for ring-magnet sensing. Superior high-temperature performance is made possible through an Allegro patented dynamic offset cancellation that utilizes chopper-stabilization. This method reduces the offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress. The A3230 includes the following on a single silicon chip: a voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trigger, and a short circuit protected open-drain output. Advanced BiCMOS wafer fabrication processing takes advantage of low-voltage requirements, component matching, very low input-offset errors, and small component geometries. Packages: 3 pin SOT23W (suffix LH), and 3 pin SIP (suffix UA) The A3230 Hall-effect bipolar switch turns on in a south polarity magnetic field of sufficient strength and switches off in a north polarity magnetic field of sufficient strength. Because the output state is not defined if the magnetic field is www.DataSheet4U.com Continued on the next page… Not to scale Functional Block Diagram VCC Regulator To All Subcircuits Sample and Hold Dynamic Offset Cancellation Low-Pass Filter VOUT Amp Control Current Limit <1Ω GND 3230-DS, Rev. 2 A3230 Chopper-Stabilized Hall Effect Bipolar Switch for the L temperature range. Two A3230 package styles provide magnetically optimized solutions for most applications. Package LH is a SOT23-W, a miniature low-profile surface-mount package, while package UA is a three-lead ultramini SIP for through-hole mounting. Each package is available in a lead (Pb) free version, with 100% matte tin plated leadframes. Description (continued) diminished or removed, to ensure that the device switches, Allegro recommends using magnets of both polarities and of sufficient strength in the application. The A3230 is rated for operation between the ambient temperatures –40°C and 85°C for the E temperature range, and –40°C to 150°C Selection Guide Part Number A3230ELHLT-T A3230EUA-T A3230LLHLT-T A3230LUA-T 1Pb-based Pb-free1 Yes Yes Yes Yes Packing2 7-in. reel, 3000 pieces/reel Bulk, 500 pieces/bag 7-in. reel, 3000 pieces/reel Bulk, 500 pieces/bag Mounting 3-pin SOT23W surface mount 3-pin SIP through hole 3-pin SOT23W surface mount 3-pin SIP through hole Ambient, TA (°C) –40 to 85 BRP(MIN) (G) –25 BOP(MAX) (G) 25 –40 to 150 variants are being phased out of the product line. 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: A3230ELHLT, A3230EUA, A3230LLHLT, and A3230LUA. for additional packing options. 2Contact Allegro Absolute Maximum Ratings Characteristic Supply Voltage Reverse Supply Voltage Output Off Voltage Output Current Reverse-Output Current Magnetic Flux Density Operating Ambient Temperature Maximum Junction Temperature Storage Temperature Symbol VCC VRCC VOUT IOUTSINK IROUT B TA TJ(max) Tstg Range E Range L Notes Rating 28 –18 26.5 Internally Limited –10 Unlimited –40 to 85 –40 to 150 165 –65 to 170 Units V V V – mA G ºC ºC ºC ºC Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 A3230 Chopper-Stabilized Hall Effect Bipolar Switch OPERATING CHARACTERISTICS valid over full operating voltage and ambient temperature ranges, unless otherwise noted Characteristic Electrical Characteristics Supply Voltage1 Output Leakage Current Output On Voltage Output Current Limit Power-On Time Chopping Frequency Output Rise Time2 Output Fall Time2 Supply Current Reverse Battery Current Supply Zener Clamp Voltage Supply Zener Current3 Magnetic Characteristics4 Operate Point Release Point Hysteresis 1 Symbol VCC IOUTOFF VOUT(SAT) IOM tPO fc tr tf ICCON ICCOFF IRCC VZ IZ BOP BRP BHYS Test Conditions Operating, TJ < 165°C VOUT = 24 V, B < BRP IOUT = 20 mA, B > BOP B > BOP VCC > 3.6 V RLOAD = 820 Ω, CS = 20 pF RLOAD = 820 Ω, CS = 20 pF B > BOP B < BRP VRCC = –18 V ICC = 6.5 mA; TA = 25°C VS = 28 V South pole adjacent to branded face of device North pole adjacent to branded face of device BOP – BRP Min. 3.6 – – 30 – – – – – – – 28 – –10 –25 5 Typ. – – 250 – 8 200 0.2 0.2 1.6 1.6 – – – 7.5 –7.5 15 Max. 24 10 500 60 50 – 1 1 3.5 3.5 –2 – 6.5 25 10 25 Units V μA mV mA μs kHz μs μs mA mA mA V mA G G G Maximum voltage must be adjusted for power dissipation and junction temperature, see Power Derating section. 2 C = oscilloscope probe capacitance. S 3 Maximum current limit is equal to the maximum I CC(MAX) + 3 mA. 4 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). DEVICE QUALIFICATION PROGRAM Contact Allegro for information. EMC (Electromagnetic Compatibility) REQUIREMENTS Contact Allegro for information. Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 A3230 Chopper-Stabilized Hall Effect Bipolar Switch Electrical Characteristic Data Supply Current (On) versus Ambient Temperature 5.0 4.0 5.0 4.0 Supply Current (On) versus Supply Voltage ICCON (mA) 3.0 2.0 1.0 0 –50 0 50 TA (°C) 100 150 ICCON (mA) VCC (V) 24 3.6 TA (°C) –40 25 150 3.0 2.0 1.0 0 0 5 10 VCC (V) 15 20 25 Supply Current (Off) versus Ambient Temperature Supply Current (Off) versus Supply Voltage 5.0 4.0 5.0 4.0 ICCOFF (mA) ICCOFF (mA) VCC (V) 3.0 2.0 1.0 0 –50 0 50 TA (°C) 100 150 24 3.6 TA (°C) –40 25 150 3.0 2.0 1.0 0 0 5 10 VCC (V) 15 20 25 Output Voltage (On) versus Ambient Temperature 500 450 400 350 500 450 400 350 Output Voltage (On) versus Supply Voltage VOUT(SAT) (mV) VOUT(SAT) (mV) 300 250 200 150 100 50 0 –50 0 50 TA (°C) 100 150 VCC (V) 24 3.6 300 250 200 150 100 50 0 0 5 10 VCC (V) 15 20 25 TA (°C) –40 25 150 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 4 A3230 Chopper-Stabilized Hall Effect Bipolar Switch Magnetic Characteristic Data Operate Point versus Ambient Temperature 25 20 15 25 20 15 VCC (V) 24 3.8 Operate Point versus Supply Voltage BOP (G) BOP (G) 10 5 0 -5 -10 –50 0 50 TA (°C) 100 150 10 5 0 -5 -10 0 5 10 VCC (V) 15 20 25 TA (°C) –40 25 150 Release Point versus Ambient Temperature 10 5 0 10 5 0 VCC (V) 24 3.8 Release Point versus Supply Voltage BRP (G) -10 -15 -20 -25 –50 0 50 TA (°C) 100 150 BRP (G) -5 -5 TA (°C) –40 25 150 -10 -15 -20 -25 0 5 10 VCC (V) 15 20 25 Hysteresis versus Ambient Temperature 25 25 Hysteresis versus Supply Voltage 20 20 BHYS (G) BHYS (G) VCC (V) 15 24 3.8 TA (°C) 15 –40 25 150 10 10 5 –50 0 50 TA (°C) 100 150 5 0 5 10 VCC (V) 15 20 25 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 5 A3230 Chopper-Stabilized Hall Effect Bipolar Switch THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions* Package LH, 1-layer PCB with copper limited to solder pads Package Thermal Resistance RθJA Package LH, 2-layer PCB with 0.463 in.2 of copper area each side connected by thermal vias Package UA, 1-layer PCB with copper limited to solder pads *Additional thermal information available on Allegro Web site. Value Units 228 110 165 ºC/W ºC/W ºC/W 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 20 VCC(max) Maximum Allowable VCC (V) 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) VCC(min) 120 140 160 180 40 60 80 100 Temperature (ºC) 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 20 Power Dissipation, PD (m W) 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 ) 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 A3230 Chopper-Stabilized Hall Effect Bipolar Switch Functional Description Operation The output of these devices switches low (turns on) when a magnetic field perpendicular to the Hall sensor exceeds the operate point threshold, BOP. After turn-on, the output voltage is VOUT(SAT). The output transistor is capable of sinking current up to the short circuit current limit, IOM, which is a m