We have used OPA 1678 For microphone ,we want to the Frequency Response as attachment {Frequency Response of OPA 1678 }.But the actual Frequency Response as attchment {The actual Frequency Response }. Our schematic diagram as attachment {OPA1678 - DEMO}.Please check for us ，Give us advice！ THANKS
At present, our situation is:
If OPA1678 pin 7 is connected to VCC without circuit ,Making a three-terminal operational amplifier can work normally.
But if it is changed to two-terminal op-amp, the attached waveform will appear.
But if we change to two-terminal operational amplifier, as shown in the attached circuit diagram, the attached picture waveform will appear. Reduction of magnification
What is the way to increase the amplification factor under the two-terminal amplifier circuit?
We have use OPA1678 for Automotive Audio. We want a Frequency Response of MIC as follow :
But ,the actual Frequency Response as follow:
Our schematic diagram as attachment . Please check it for us ,Thanks ! Please suggest how to debug OPA1678 - DEMO.pdf
