ams AG - global leader in the design and manufacture of high performance analog ICs (integrated circuits)

TSL235 Light-to-Frequency

Converter sidelooker package


The TSL235R light-to-frequency converter combines a silicon photodiode and a current-to-frequency converter on a single monolithic CMOS integrated circuit. Output is a square wave (50% duty cycle) with frequency directly proportional to light intensity (irradiance) on the photodiode. The digital output allows direct interface to a microcontroller or other logic circuitry. The device has been temperature compensated for the ultraviolet-to-visible light range of 320 nm to 700 nm and responds over the light range of 320 nm to 1050 nm. The TSL235R is characterized for operation over the temperature range of −25°C to 70°C and is supplied in a 3-lead clear plastic side-looker package with an integral lens. When supplied in the lead (Pb) free package, the device is RoHS compliant.

Key Features

  • 1M:1 input dynamic range
  • Low dark frequency of 0.4 Hz (Typ)
  • High Irradiance Responsivity 0.6kHz/(µW/cm2) @ λp = 635nm
  • 2X gain lense

Key Benefits

  • Detects light intensity at a high resolution
  • Provides low light level operation 
  • Provides for high sensitivity to detect a small change in light 
  • Provides additional sensitivity advantages

Product Facts

Supply Voltage [V] 2,7-5,5
Responsivity [Hz/uW/cm²] 625 @ 635
Output Frequency [Max.] 500 KHz
Selectable Sensitivity and Full-scale Output Frequency
Output Frequency Tolerances [+/- %] 20
Temperature Range [°C] -25 to 70
Packages S

Additional Information

  • ▪ Pulse oximetry
  • ▪ Color sensing
  • ▪ Turbidity sensing
  • ▪ Optical Switch