The inputs of the OPA177 are protected with 500‑Ω series input resistors and diode clamps as shown in the simplified circuit diagram on the front page. The inputs can withstand ±30‑V differential inputs without damage. The protection diodes conduct current when the inputs are overdriven. This conducted current can disturb the slewing behavior of unity-gain follower applications, but does not damage the op amp. Some applications, such as programmable logic controllers (PLCs) require a robust input-protection design. An input-protection circuit can be implemented using four Schottky diodes; however, the temperature and voltage dependent leakage of the diodes can present undesirable nonlinear errors at the input. For applications requiring high precision and robust input protection, the OPAx206 family of op amps are an excellent choice, offering integrated input overvoltage protection that eliminates the need for external clamping circuits.