Patent ID: 6686779
Filing Date: 2004-02-03
Classification: H03K,H04L

Abstract:
A driver circuit, comprising:a constant current section for outputting a prescribed positive or negative current; a first pad capable of being connected to the other end of a first resistor, the first pad having one end connected to a first node receiving a first voltage; a second pad capable of being connected to the other end of a second resistor, the second pad having one end connected to the first node; a first switching element connected between an output node of the constant current section and the first pad and turned ON/OFF in response to a first signal; a second switching element connected between the output node of the constant current section and the second pad and turned ON/OFF in response to a second signal that is complementary to the first signal; and a control section for controlling a potential at the output node of the constant current section to a prescribed potential, wherein the control section varies an on-state resistance value of the first and second switching elements according to the potential at the output node of the constant current section, and the first switching element includes first and second transistors connected in parallel between the output node of the constant current section and the first pad and turned ON/OFF in response to the first signal, the second switching element includes third and fourth transistors connected in parallel between the output node of the constant current section and the second pad and turned ON/OFF in response to the second signal, and the control section activates and inactivates the first to fourth transistors according to the potential at the output node of the constant current section.