High-speed serial port load automatic calibration circuit

• Main Authors: ZHANG QINFENG, TANG SAINAN, JIANG YINGDAN, WAN SHUQIN, SU XIAOBO, YANG XIAOLEI, LIANG QI
• Format: Patent
• Language: English
• Published: 02.12.2015
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; PULSE TECHNIQUE

The invention relates to a high-speed serial port load automatic calibration circuit. One end of a port load resistor array of the high-speed serial port load automatic calibration circuit is connected with an analog power supply, the other end is connected with an input end of a first current source, and an output end of the first current source is connected to the ground; one end of a high-precision resistor is connected with an analog power supply, the other end is connected with an input end of a second current source, and an output end of the second current source is connected to the ground; one end of a high-speed serial port resistor array is connected with an analog power supply; a negative input end of a comparator is connected between the port load resistor array and the first current source, a positive input end is connected between the high-precision resistor and the second current source, the comparator compares voltage values of the high-precision resistor and the port load resistor array and outputs a comparison result signal to a digital state machine, the digital state machine generates a control signal to control resistance of the port load resistor array and the high-speed serial port resistor array. The high-speed serial port load automatic calibration circuit provided by the invention realizes automatic calibration of the high-speed serial port load resistor, and achieves an impedance matching effect of a high-speed serial port.