The FET-inputs of the OPAx132 series provide very low input bias current and cause negligible errors in most applications. For applications where low input bias current is crucial, minimize junction temperature rise. The input bias current of FET-input operational amplifiers increases with temperature; see also Figure 5-5.

The OPAx132 series can be operated at reduced power supply voltage to minimize power dissipation and temperature rise. Using ±3V supplies reduces power dissipation to one-fifth used at ±15V.

The dual and quad versions have higher total power dissipation than the single version, leading to higher junction temperature. Thus, a warmed-up quad has higher input bias current than a warmed-up single. Furthermore, an SOIC generally has higher junction temperature than a DIP at the same ambient temperature because of a larger θ_JA.

Printed-circuit-board (PCB) layout also helps minimize junction temperature rise. Minimize temperature rise by soldering the devices to the PCB rather than using a socket. Wide copper traces also help dissipate the heat by acting as an additional heat sink.

Input stage cascode circuitry keeps the input bias current virtually unchanged throughout the full input common-mode range of the OPAx132 series. See also Figure 5-6.