SBOS957F February 2022 – October 2025 OPA2328 , OPA328 , OPA4328
PRODMIX
The OPAx328 incorporate internal electrostatic discharge (ESD) protection circuits on all pins. In the case of input and output pins, this protection primarily consists of current-steering diodes connected between the input and power-supply pins. These ESD protection diodes also provide in-circuit input overdrive protection if the current is limited to 10 mA. Many input signals are inherently current-limited to less than 10 mA; therefore, a limiting resistor is not required. Figure 6-1 shows how a series input resistor (RIN) can be added to the driven input to limit the input current. The added resistor contributes thermal noise at the amplifier input; therefore, keep this value to a minimum in noise-sensitive applications.