I have a dual-supply op-amp (±12V) that outputs a signal in the range of ±3V. I cannot neither change the op-amp configuration nor add another one. Please not the schematic below is just an example. The actual configuration is more complex, but it doesn't matter about the question.
The output goes to a voltage divider and I need to clip the negative voltages.
The common way is to add a diode on the output:
But when the output swings below the threshold voltage nothing limits the current.
Where should I put a limiting resistor?
- in series to the diode? I think it will affect the clipping
- on the op-amp output, after the fb node? I think it will affect the resister divider
- on the op-amp output, before the fb node? I'm afraid it will affect the feedback gain
Is there a better way to achieve this?