A1225

A1225, A1227, and A1229 Hall Effect Latch for High Temperature Operation Features and Benefits ▪ Symmetrical switchpoints ▪ Superior temperature stability ▪ Operation from unregulated supply ▪ Open-drain 25 mA output ▪ Reverse Battery protection ▪ Activate with small, commercially available permanent magnets ▪ Solid-state reliability ▪ Small size ▪ Resistant to physical stress ▪ Enhanced ESD structures result in 8 kV HBM ESD performance without external protection components ▪ Internal protection circuits enable 40 V load dump compliance without external protection components Description These Hall-effect latches are extremely temperature-stable and stress resistant sensor ICs especially suited for operation over extended temperature ranges to 150°C. Superior hightemperature performance is made possible through a novel Schmitt trigger circuit that maintains operate and release point symmetry by compensating for temperature changes in the Hall element. Additionally, internal compensation provides magnetic switchpoints that become more sensitive with temperature, hence offsetting the usual degradation of the magnetic field with temperature. The symmetry capability makes these devices ideal for use in pulse-counting applications where duty cycle is an important parameter. The three basic devices (A1225, A1227, and A1229) are identical except for magnetic switchpoints. Each device includes on a single silicon chip a voltage regulator, Hall-voltage generator, temperature compensation circuit, signal amplifier, Schmitt trigger, and a buffered open-drain output to sink up to 25 mA. The on-board regulator permits operation with supply voltages of 3.8 to 24 V. The first character of the part number suffix determines the device operating temperature range. Suffix L is for –40°C to 150°C. Two package styles provide a magnetically optimized package for most applications. Suffix LT is a miniature SOT89/ TO-243AA transistor package for surface-mount applications, suffix UA is a three-lead ultra-mini-SIP. Both packages are lead (Pb) free with 100% matte tin leadframe plating. Packages: 3-pin SOT89 (suffix LT) and 3-pin SIP (suffix UA) Not to scale Functional Block Diagram VCC Regulator To All Subcircuits Clock / Logic VOUT Hall Chopping Logic AMP Anti-aliasing LP-Filter Tuned Filter GND A1225-DS A1225, A1227 and A1229 Hall Effect Latch for High Temperature Operation Selection Guide Part Number A1225LLTTR-T A1225LUA-T A1227LLTTR-T A1227LUA-T A1229LLTTR-T A1229LUA-T Packing* 7-in. reel, 1000 pieces/reel Bulk, 500 pieces/bag 7-in. reel, 1000 pieces/reel Bulk, 500 pieces/bag 7-in. reel, 1000 pieces/reel Bulk, 500 pieces/bag Package 3-pin SOT89 surface mount 3-pin SIP through hole 3-pin SOT89 surface mount 3-pin SIP through hole 3-pin SOT89 surface mount 3-pin SIP through hole Ambient Temperature, TA –40°C to 150°C –40°C to 150°C –40°C to 150°C BRP(min) (G) –300 –175 –200 BOP(max) (G) 300 175 200 *Contact Allegro® for additional packaging options. Absolute Maximum Ratings Characteristic Forward Supply Voltage Reverse Supply Voltage Output Off Voltage Reverse Output Voltage Continuous Output Current Operating Ambient Temperature Maximum Junction Temperature Storage Temperature Symbol VCC VRCC VOUT VROUT IOUT(SINK) TA TJ(max) Tstg Range L Notes Rating 30 –30 30 –0.5 25 –40 to 150 165 –65 to 170 Unit V V V V mA ºC ºC ºC Pin-out Diagrams Package LT Package UA Terminal List Table Number 1 2 3 Name VCC GND VOUT Function Input power supply Ground Output signal 1 2 3 1 2 3 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 A1225, A1227 and A1229 Hall Effect Latch for High Temperature Operation ELECTRICAL CHARACTERISTICS Valid at TA = –40°C to 150°C, CBYPASS = 0.1 μF, VCC = 12 V; unless otherwise noted Characteristics Electrical Characteristics Supply Voltage Supply Current Supply Zener Voltage Reverse Battery Current Power-On Time3 Power-On State Chopping Frequency Output Stage Characteristics Output Saturation Voltage Output Leakage Current Output Rise Time3,4 Output Fall Time3,4 Output Zener Voltage Magnetic Characteristics A1225 Operate Point BOP A1227 A1229 A1225 Release Point BRP A1227 A1229 A1225 Hysteresis (BOP – BRP) BHYS A1227 A1229 1Typical 21 Symbol VCC ICC VZ(sup) IZ(sup) tPO POS fchop VOUT(sat) IOFF tr tf VZ(out) IOUT = 20 mA B < BOP Test Conditions Operating; TJ ≤ 165°C B < BRP (Output off) B > BOP (Output on) ICC = 9 mA, TA = 25°C VRCC = –28 V, TA = 25°C Min. 3.8 – – 28 –5 – – – – – – – 30 170 140 50 50 100 80 –270 –300 –150 –175 –180 –200 340 280 100 100 200 160 Typ.1 Max. 24 Unit2 V mA mA V mA μs – kHz mV μA ns ns V G G G G G G G G G G G G G G G G G G – – – – – HIGH 400 175