I use a piezo to register the moment of a knock via a micro controller's analog in (1.8V Max) So far I used the scheme in the figure without any diodes. This works so far, but depending on the knocks harshness, the op-amp cuts the sensor signal. This is why I want to protect the op-amps in+ from overvoltage.
I have two questions:
- will two back back zener-diodes 5.1 V protect my op-amp sufficiently?
- if yes: Does anyone know smt diodes which are quiet big, like 3 mm or so.