Patent ID: 8884661
Filing Date: 2014-11-11
Classification: H03K

Abstract:
1. A driver circuit comprising a serially connected high side output transistor and low side output transistor each driven on and off based on a control input pulse signal, and outputting a signal driving a power semiconductor device from a series connection point of the transistors, the driver circuit further comprising: a high side first stage drive circuit, into which a first on/off signal is input, that outputs a first control signal on/off driving the high side output transistor; a low side first stage drive circuit, into which a second on/off signal is input, that outputs a second control signal on/off driving the low side output transistor; a detector circuit, connected in parallel to the series circuit of the high side output transistor and low side output transistor, that includes a high side detection transistor, a resistor, and a low side detection transistor connected in series; a clamping circuit that converts a high voltage amplitude change signal generated at a connection point of the high side detection transistor and resistor in the detector circuit to a signal clamped to a voltage range applied on the low side; a first logic circuit that allows the control input pulse signal to pass through when the second control signal is a signal causing the low side output transistor to be turned off; a level shifter circuit that shifts the level of an output signal of the first logic circuit, and outputs the signal as the first on/off signal; and a second logic circuit that allows the control input pulse signal to pass through when an output signal of the clamping circuit is at an L level, outputting the control input pulse signal as a second on/off signal, wherein the high side detection transistor is driven on and off simultaneously with the high side output transistor by the first control signal, and the low side detection transistor is turned on when the control input pulse signal is a signal commanding a turning on of the low side output transistor or a signal commanding a turning off of the high side output transistor, and the low side detection transistor is turned off when the control input pulse signal is a signal commanding a turning off of the low side output transistor or a signal commanding a turning on of the high side output transistor.