Patent ID: 6621679
Filing Date: 2003-09-16
Classification: H01L

Abstract:
A corner clamp comprising:a clamp circuit connected to an electrostatic discharge (ESD) plus ring and an ESD minus ring, the clamp circuit having: a timing circuit, the timing circuit having a resistive element connected to the ESD plus ring and a first node; a pre-driver circuit connected to the timing circuit, the pre-driver circuit including a first transistor connected to the ESD plus ring, the first transistor turning on when a difference between a voltage on the ESD plus ring and a voltage on the first node exceeds a predetermined amount; and a switching circuit connected to the pre-driver circuit, the ESD plus ring, and the ESD minus ring; and a keep off circuit connected to the clamp circuit, the keep off circuit having: a control circuit connected to the first node and a shield node, the control circuit having an output; and a keep off transistor connected to the ESD plus ring, the first node, and the output of the control circuit, the keep off transistor providing a current path from the ESD plus ring to the first node when turned on.