The ISL29501 is a Time of Flight (ToF) based signal processing integrated circuit. The sensor enables low cost, low power and long range optical distance sensing when combined with an external emitter and detector.

The ISL29501 has a built-in current DAC circuit that drives an external LED or laser. The modulated light from the emitter is reflected off the target and is received by the photodiode. The photodiode then converts the returned signal into current, which is used by the ISL29501 for signal processing.