Low Voltage (LV) Overvoltage Protection
Posted: Mon Nov 16, 2020 4:53 am
TL:DR
Is there a recommended circuit (e.g. diode clamp) that folks have used or recommend to fully leverage the ADC in the LV position? I need full resolution in this range but transient signals can exceed 1V.
Extended Question:
I have an application that uses a high gain, current-voltage amplifier (10^9) to measure transient currents in the pA range. However, to do so the experiment requires the pulsing of a high voltage electrode which capacitively couples with the detector. While very short (i.e. 10s of ns), this coupling can cause the amplifier to output voltages that exceed 1V. Additional information worth mentioning is that the signals I'm trying to measure have rise times in the 100s of ns range. Because the voltages of the true signal rarely exceed 1V, I really need the resolution in the LV setting.
Are there any recommended circuits that would help protect the ADCs without sacrificing sampling performance too much? Ultimately, I'd like to sample with a decimation of 1024.
Relevant links that I've considered but haven't tried as I don't want to break things include:
https://www.eevblog.com/forum/projects/ ... ode-clamp/
https://forum.arduino.cc/index.php?topic=611356.0
Cheers
Is there a recommended circuit (e.g. diode clamp) that folks have used or recommend to fully leverage the ADC in the LV position? I need full resolution in this range but transient signals can exceed 1V.
Extended Question:
I have an application that uses a high gain, current-voltage amplifier (10^9) to measure transient currents in the pA range. However, to do so the experiment requires the pulsing of a high voltage electrode which capacitively couples with the detector. While very short (i.e. 10s of ns), this coupling can cause the amplifier to output voltages that exceed 1V. Additional information worth mentioning is that the signals I'm trying to measure have rise times in the 100s of ns range. Because the voltages of the true signal rarely exceed 1V, I really need the resolution in the LV setting.
Are there any recommended circuits that would help protect the ADCs without sacrificing sampling performance too much? Ultimately, I'd like to sample with a decimation of 1024.
Relevant links that I've considered but haven't tried as I don't want to break things include:
https://www.eevblog.com/forum/projects/ ... ode-clamp/
https://forum.arduino.cc/index.php?topic=611356.0
Cheers