HELP!!! OP295 Not Amplifying

[oiyela]

Hi,
my project involves finding the heart rate of a patient, through using an infrared emitter and a photo diode to detect the change in infrared signals. basically the output of the photo diode is in milivolts and to be able to read the pulses(due to change in infrared signals) with the micro controller, the output of the photo diode have to be amplified. i have bought the OP295 op-amp to do this, my issue is that it is not working with the circuit so i decide to do further test. i put negative input to 0.1V and the positive input to 0.1V with a power supply of 5V, the output should be 0V but instead i am getting 5V as an output. i am really confused please i need to get this working.. HELP

Here is the datasheet for the OP295 - https://www.analog.com/en/all-operational-amplifiers-op-amps/operational-amplifiers-op-amps/op295/products/product.html


Thanks

 

[FvM]

i put negative input to 0.1V and the positive input to 0.1V with a power supply of 5V, the output should be 0V but instead i am getting 5V as an output.

Where did you conclude this assumption? You need to apply a voltage difference larger than specified offset voltage to drive the output to saturation with known level. To check amplifier operation, you'll preferably connect the OP in a feedback circuit.