ESD protection on small signal inputs
Diode clamps (eg. back-to-back diodes to ground after some series resistance such as 100 ohms) are probably your best bet if your input impedance is &lt; 10K. Ordinary 1N4148 diodes or a BAV99 dual will do. If the leakage at high temperature is deemed to be excessive, then just hang two or three in series. Here's what the typical leakage looks like at 0/25/50/75°C for 2 pairs in series back-to-back (4 diodes) with input voltage varying from 0mV to 50mV. 120nA makes your input appear as 9.77K rather than 10K, probably not a big deal.