Overview: A1140/41/42/43 Sensitive Two-Wire Chopper-Stabilized Unipolar Hall-Effect Switches Package LH, 3-pin SOT
3 1. VCC 2. No connection 3. GND NC 1 2 Package UA, 3-pin SIP 1. VCC 2. GND 3. GND PTCT 1 2 3 ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VCC .......................................... 28 V Reverse-Supply Voltage, VRCC ........................ –18 V Magnetic Flux Density, B .........................Unlimited Operating Temperature
Ambient, TA, Range E.................. –40ºC to 85ºC Ambient, TA, Range L................ –40ºC to 150ºC Maximum Junction, TJ(max)........................165ºC Storage Temperature, TS .................. –65ºC to 170ºC The A1140, A1141, A1142, and A1143 devices are sensitive, two-wire, unipolar, Hall effect switches that are factory-programmed at end-of-line to optimize magnetic switchpoint accuracy. These devices are produced on the Allegro MicroSystems advanced BiCMOS wafer fabrication process, which implements a patented, high-frequency, chopper-stabilization technique that achieves magnetic stability and eliminates the offsets that are inherent in single-element devices exposed to harsh application environments. Commonly found in a number of automotive applications, the A1140-43 family of devices are utilized to sense: seat track position, seat belt buckle presence, hood/trunk latching, and shift selector position.
Two-wire unipolar switches are particularly advantageous in price-sensitive applications, because they require one less wire than the more traditional open-collector output switches. Additionally, the system designer gains inherent diagnostics because output current normally flows in either of two narrowly-specified ranges. Any output current level outside of these two ranges is a fault condition.
