Other Parts Discussed in Thread: OPA365, TLV9062, OPA2172
Hi there,
I'm in a development phase of a project in which I need to amplify the received output from a piezo element(ultrasonic). I am getting the raw output(without amplification) ~40mVp-p. The excitation of the transmitter piezo is 200kHz, 12Vp-p square wave.
I am testing with TL082 dual opamp for the amplification of this signal. Since the limitation of the GBWP of 8MHz[Edit: 3MHz], I am using two stage amplification with a gain of 15(both stages).
Supply voltage is 12V. When I turn on the power supply, the amplified signal looks good, but after some time(~5 mins) the amplified signal goes off and seems like the raw signal. If I restarts the power supply, the amplified signal becomes good again.
Question No.1 - What could be the problem behind this strange behavior?
The circuit is given below,
Input and output waveforms are,
Question No. 2 - Will it be better to use opamp with higher GBWP like OPA365, in which I can use opamp in higher gain like 100?
Regards,
Harish KS