Improving the Phototransistor output for pulse signals

Discussion in 'The Projects Forum' started by Tricky, Oct 13, 2013.

  1. Tricky

    Thread Starter New Member

    May 13, 2012
    I am working with the design of pulse oximeter and as a first part made the circuit with IR led for pulse detection using the NJL5501R and opamp OPA380.
    The circuit in this link is same as the practically implemented one except OPA380 used in place of MCT60.I got the response form the phototransistor as this .
    And the output of OPA380 is not amplified rather it is very bad compared to the output signal of the phototransistor.
    Can someone help with the correction in the circuit so that the signal from phototransistor can be improved by amplification or filtering (if needed) as the final result pulse signal is used to feed the microcontroller.
    The datsheet of both are attached below