I have a simple current to voltage converter amplifier circuit with a feedback gain fo 10K with a parallel 100pF for stability / bandwidth reduction.
For some reason the amplifiers output saturates when powered up and i cant bring it back down, despite driving the input current negative. This didnt not happen for lower gains
I have the supplies well decoupled with an RC (50OHM/10uF) filter, and another 100nF at the pins.
I have a simple current to voltage converter amplifier circuit with a feedback gain fo 10K with a parallel 100pF for stability / bandwidth reduction.
For some reason the amplifiers output saturates when powered up and i cant bring it back down, despite driving the input current negative. This didnt not happen for lower gains
I have the supplies well decoupled with an RC (50OHM/10uF) filter, and another 100nF at the pins.
Picture attached, as I mentioned i have 10K in place of the 100K.
Things that I have already tried
1) Shorting inputs together, and to AGND
2) Applying negative bias current (i.e. change to unity gain inverting amp)
3) Lowering the gain, seems to work for a gain around 300 OHM
Maybe its also worth mentioning that the amplifier is in a quad QFN package. Analog devices AD8643
Shorting the inputs won't work since that generates an open loop situation and the offset voltage can still saturate the output.
If the output is high then you want a postive current applied at the inverting input, not a negative current to reduce the output. The circuit is an inverter.