This is a programmable light to frequency IC from TAOS that outputs a pulse train or a square wave (50% duty) with the frequency that is directly proportional to the incident light intensity. Uses a simple TTL output for easy interfacing to a microcontroller.

Three different sensitivity selections and four different frequency scaling parameters.

The TSL230R−LF, TSL230AR−LF, and TSL230BR−LF programmable light-to-frequency converters combine a configurable silicon photodiode and a current-to-frequency converter on single monolithic CMOS integrated circuits. The output can be either a pulse train or a square wave (50% duty cycle) with frequency directly proportional to light intensity. Device sensitivity is selectable in three ranges, providing two decades of adjustment. The full-scale output frequency can be scaled by one of four preset values. All inputs and the output are TTL compatible, allowing direct two-way communication with a microcontroller for programming and output interface. An output enable (OE) is provided that places the output in the high-impedance state for multiple-unit sharing of a microcontroller input line.

The devices are available with absolute-output-frequency tolerances of ±5% (TSL230BR−LF), ±10% (TSL230AR−LF), or ±20% (TSL230R−LF). They have been temperature compensated for the ultraviolet-to-visible light range of 320 nm to 700 nm and respond over the light range of 320 nm to 1050 nm. The devices are characterized over the temperature range of −25°C to 70°C.

Features:
  - Supply voltage 2.7 - 5.5VDC
  - 320nm - 1050nm response range
  - 2mA supply current in power on mode
  - 5uA current in power down mode mode
  - Temperature compensated for UV to visible range