Output circuits with electrostatic discharge protection

摘要

An output circuit is provided and includes first and second output stage elements, a detection circuit, a control circuit, and a first pre-driver. The first and second output stage elements are coupled in series between a power terminal and the ground terminal. The detection circuit detect whether an electrostatic discharge event occurs at an output terminal between the two output stage elements to generate a control signal. The control circuit controls a state of the first output stage element when the control circuit is enabled according to the control signal. The first pre-driver controls the state of the first output stage element when the first per-driver is enabled according to the control signal. When the detection circuit detects that the electrostatic discharge event occurs at the output terminal, the control circuit is enabled to turn on the first output stage element, and the first pre-driver is disabled.

主权项

1. An output circuit comprising:
a first output stage element coupled to an output terminal of the output circuit and a ground terminal; a second output stage element coupled to the output terminal and a power terminal; a detection circuit, coupled to the power terminal, for performing a detection operation to detect whether an electrostatic discharge event occurs at the output terminal to generate a control signal (S12) at a first node, wherein the detection circuit comprises: a resistor coupled between the power terminal and the first node; and a capacitor coupled to the first node and the ground terminal, wherein the control signal is generated at the first node; a control circuit, directly connected to the first node, for receiving the control signal and controlling a state of the first output stage element when the control circuit is enabled according to the control signal; and a first pre-driver for receiving the control signal and controlling the state of the first output stage element when the first pre-driver is enabled according to the control signal, wherein when the detection circuit detects that the electrostatic discharge event occurs at the output terminal, the control circuit is enabled according to the control signal to turn on the first output stage element to form a discharge path, and the first pre-driver is disabled according to the control signal.