Automotive GMR sensor interface ASIC for speed and direction measurement

Automotive GMR sensor interface ASIC for speed and direction measurement

The low-power GMR (giant magneto resistive) readout ASIC is co-integrated with the GMR sensors on a single die and it is used for crankshaft and transmission speed and direction sensing. It contains a speed and a direction analog readout channel, a multiplexed SAR ADC and a digital processing unit, containing an adaptive algorithm for vibration and air gap variation tolerant sensing and direction detection and PWM communication with the car’s control unit.

FEATURES:

  • GMR (Giant Magneto Resistive) sensor readout ASIC
  • Wheatstone bridge signal conditioning
  • Digital processing included
    • Air gap variation tolerant
    • Vibration tolerant sensing
    • Direction detection
    • Dynamic self calibration
  • Low power (2.5V Vdd in 0.65um technology)
  • Low jitter performance
  • High sensitivity and large air gap capability
  • Large frequency range (up to 15 kHz)
  • Three-wire digital voltage interface (PWM)
  • VHDL-AMS modelling of the sensor by ICsense
  • Multiplexed 200 kS/s 12-bit SAR ADC
  • AEC-Q100 qualified
  • Temperature range -40°C to 200°C
  • 0.65um BiCMOS technology
  • Module style package with two integrated capacitors:
    • 4.7nF between Q and GND
    • 47nF between Vs and GND