Patent ID: 8335066
Filing Date: 2012-12-18
Classification: H02H

Abstract:
1. A protection circuit connected between an interface circuit and a main circuit of an electronic device, the interface circuit for providing a path for a power supply to power the main circuit, the protection circuit comprising: an electrostatic protection unit electrically connected to the interface circuit and the main circuit, the electrostatic protection unit configured for clamping a voltage of a node to a predetermined value, which the node is defined by the interface circuit, the electrostatic protection unit, and the main circuit; and a mis-connect protection unit electrically connected between the node and the main circuit, when the interface circuit is incorrectly connected to the power supply, the mis-connect protection unit disconnects an electrical connection between the power supply and the main circuit; wherein the electrostatic protection unit comprises a voltage dependent resistor, one end of the voltage dependent resistor is electrically connected to the node, the other end of the voltage dependent resistor is always electrically grounded.