microsystems on silicon


PIR Signal Processor


The E931.08 integrated circuit is specifically designed for interfacing Passive Infra-red Sensors with micro controllers or processors. The serial communications with the micro controller uses only 1 pin. Multiple E931.08 devices can easily be operated at the same time.

One or 2 PIR sensor can be connected to the two PIRIN analog inputs of the device. The differential signal is converted to a digital value using a high resolution sigma-delta converter in combination with advanced DSP techniques. The 17 bit digital ADC value is made available to an external micro controller via a single wire serial interface (DOCITM).

The E931.08 allows longer distances between the PIR and the micro controller. The signal processing on the micro controller is reduced due to the integrated low pass filter on the E931.08.


  • Advanced and normal movement detectors
  • Energy savings applications


  • 14 bit chip temperature measurement
  • High resolution
  • Fast settling time
  • Single wire serial interface (DOCITM)
  • Operating voltage down to 2.7V
  • Low current consumption
  • High Signal to Noise ratio
  • High power supply rejection