Patent ID: 6809571
Filing Date: 2004-10-26
Classification: H03K

Abstract:
A control circuit for controlling a driving circuit for driving a power device, comprising:sensing circuitry for providing a sense result signal for controlling said driving circuit in response to a sense input signal received on a sense input, the sense input signal including information received from the power device over a circuit path from said power device to said sensing circuitry; the sense result signal including information derived from the sense input signal about operation of the power device; and correction circuitry included in said circuit path from said power device to said sensing circuitry for preventing the sense input signal on said circuit path from including spurious information received from the power device, said correction circuitry comprising an active impedance element for presenting a high impedance at said sense input when said power device is on thereby allowing said spurious information to be conducted through the power device and presenting a low impedance at said sense input when said power device is off, thereby shunting said spurious information through said correction circuitry and preventing said sense input signal from including said spurious information.