Disclosed is a PPG signal measurement apparatus comprising a light source for emitting light pulses a light sensor for receiving reflected light from the light source and generating a sensor signal an electronic unit including a transimpedance amplifier and an ambient light cancelation unit, a first switch in a front end portion of the light sensor, a second switch in the front end portion of the light sensor, a microcontroller in communication with the light source, the light sensor, and the ambient light cancellation unit.
