asdf44
Advanced Member level 4
Does anyone have experience protecting <1nA current measurement circuits? Specifically a transimpedance amplifier input from transient overcurrent events.
Looking at ESD devices, diodes, zeners etc I don't see anything with specified leakage below 1nA.
On the other hand all these datasheets are specifying leakage near their breakdown voltage whereas the transimpedance topology means that during normal operation voltage will be ~0V.
And for example the circuit originally had standard back to back diodes that would simply forward bias and clamp to ~0.7V and this worked fine until at least the nA territory.
Looking at ESD devices, diodes, zeners etc I don't see anything with specified leakage below 1nA.
On the other hand all these datasheets are specifying leakage near their breakdown voltage whereas the transimpedance topology means that during normal operation voltage will be ~0V.
And for example the circuit originally had standard back to back diodes that would simply forward bias and clamp to ~0.7V and this worked fine until at least the nA territory.
