TI-105 is a stand-alone sensor integrated controller, compromising a 5 V linear voltage regulator, a photoamplifier, two generators (8192 Hz and 4 MHz), a ROM, an error correction circuit and a digital unit. 

The device’s programmable coefficients:

  • Photoamplifier gain
  • Measurements period (default mode)
  • Measurements period (preparation to fire mode)
  • Visible LED operation time
  • IR LED operation time
  • Measurements preparation time
  • Number of successive “positive” measurements before switching into fire mode
  • Standby time at loop reset
  • Audio-frequency generator coefficients


  • Power supply range: 7-18 V
  • Current consumption: 5 uA
  • Battery state control
  • Programmable measurement cycle time
  • Programmable gain
  • Optical smoke density calibration
  • Low power protection
  • ROM correction (one defective bit recovery)
  • Two bits defect indication