General Description

The MAX9921 provides a single chip solution to interface two 2-wire Hall-effect sensors to a low-voltage microprocessor (µP). This device supplies and monitors the current drawn by two Hall-effect sensors, filters the sensed current level, and outputs the corresponding logic level.

Features

♦ Withstands 60V at BAT Supply and Hall Inputs

♦ 6V to 18V Operating Voltage Range

♦ Provides Supply Current and Interfaces to Two 2-Wire Hall Sensors

♦ Error Output with Diagnostics of Hall Inputs and BAT Voltage

♦ Protects Hall Sensors from Overvoltage by Isolating Them from Supply Transients

♦ Hall Inputs Protected from Short to Ground

♦ Ramps Current to Hall Sensors at 4mA/µs

♦ Output Enable Input Allows Multiplexing of Outputs from Multiple MAX9921s

♦ Hall Output Filtering

♦ Hall Sensor Blanking Following Hall Sensor Power-Up or Restart

♦ Low-Power Shutdown, Controlled with OE and DIAG Inputs

♦ Operates with ±2V Ground Shifts Between Hall Sensor and MAX9921

Applications

   Door Modules

   Window Lifters

   Seat Movers

   Electric Sunroofs

   Powered Lift Gate Controllers

   Powered Running Boards

   Seatbelt Buckles