Features: Chopper stabilization
Low switchpoint drift over operating temperature range
Low stress sensitivity
Factory programmed at end-of-line for optimized switchpoints
On-chip protection
Supply transient protection
Reverse-battery protection
On-board voltage regulator
3.5 V to 24 V operationSpecificationsSupply 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 170ºCDescriptionThe 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. A1140, A1141, A1142, and A1143 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, A1141, A1142, and A1143 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 A1140, A1141, A1142, and A1143 require one less wire than the more traditional open-collector output switches. Additionally, the system designer gains inherent diagnostics because output current normally fl ows in either of two narrowly-specifi ed ranges. Any output current level outside of these two ranges is a fault condition. The A1140, A1141, A1142, and A1143 family of devices also features on-chip transient protection, and a Zener clamp to protect against overvoltage conditions on the supply line.
A1140 Data Sheet
