3197 Datasheet | Allegro MicroSystems

PROTECTED, HIGH-TEMPERATURE, OPEN-COLLECTOR HALL-EFFECT LATCH These open-collector Hall-effect latches are capable of sensing magnetic fields while using an unprotected power supply. The A3197LLT and A3197LU can provide position and speed information by providing a digital output for magnetic fields that exceed their predefined switch points. These devices operate down to zero speed and have switch points that are designed to be extremely stable over a wide operating temperature and voltage range. The latching characteristics make them ideal for use in pulse counting applications when used with a multi-pole ring magnet. Thermal and output short-circuit protection allow an increased wiring harness fault tolerance. The temperature pensated switch points, the wide operating voltage range, and the integrated protection make these devices ideal for use in automotive applications such as transmission speed sensors and integrated wheel bearing speed sensors. Data Sheet 27609.10A PTCT Dwg. PH-003-2 Each monolithic device contains an integrated Hall-effect transducer, a temperature-pensated parator, a voltage regulator, and a buffered 35 m A output sink stage. Supply protection is made possible by the integration of overvoltage and undervoltage shutdown circuitry that monitor supply fault conditions and shut down the IC. Noise shutdown circuitry (patent applied for) prevents the propagation of supply transients to the logic load. Output protection circuitry includes a current limit loop that limits the maximum output sink current, and thermal protection circuitry that shuts down the device during an over-heating condition such as with a shorted load. The A3197LLT and A3197LU are rated for operation over an extended temperature range of -40°C to +150°C. They are supplied in a three-lead SIP (suffix ‘U’) or a surface-mount SOT-89 (suffix...