Figure 3-1 shows the most common ESD protection structure for an op amp. Dual diodes are placed on the inputs and outputs and are routed to the supplies. The ESD diodes direct any ESD transients onto the power supply. For this reason, the diodes are often called ESD steering diodes. To prevent damage to the op amp supply, an ESD absorption device is placed across the supply. The absorption device triggers on and act as a low impedance when the ESD event occurs. Thus, the absorption device limits the voltage applied across the supply and protect the device.

Figure 3-1 Dual Diode Configuration on Op Amp Input and Output

The benefits of the dual diode configuration include low leakage and low capacitance, making the dual diode configuration a great option for most op amps. The diodes only take up a small area, and are preferred to handle high frequency inputs and outputs. However, there are certain scenarios in which the dual diode configuration is not designed for protection.