DISPLAY DATA CHANNEL INTERFACE CIRCUIT

摘要

A DDC interface circuit includes a first NMOS transistor and a second NMOS transistor. The gates of the first and the second NMOS transistors are all connected to a 3.3V system power via a first resistor. The source of the first NMOS transistor is connected to a DDC_CLK pin of a north bridge. The drain of the first NMOS transistor is connected to a 5V system power via a second resistor, and also connected to an SCL pin of a VGA interface via a third resistor to receive an ACK signal. The source of the second NMOS transistor is connected to a DDC_DATA pin of the north bridge. The drain of the second NMOS transistor is connected to the 5V system power via a fourth resistor, and also connected to an SDA pin of the VGA interface via a fifth resistor.