IMPEDANCE ADJUSTMENT CIRCUIT FOR OUTPUT DRIVER

摘要

The present invention relates to a technology capable of reducing the size of installation space and power consumption not using a regulator for pre-drivers when designing a circuit for adjusting impedance of an output driver at a voltage mode applicable to mobile industry processor interface (MIPI) specification, which is a serial interface specification used for connecting hardware and software between a processor and peripheral devices. An impedance adjustment circuit for an output driver according to the present invention comprises: an impedance control signal outputting unit configured to output a pull-up impedance control signal and a pull-down impedance control signal for adjusting changed impedance to correspond to impedance changes of devices of a pull-up device and a pull-down device in the output driver when the impedance of the devices changes according to changes in a second power voltage in the output driver; a decoder configured to output the pull-up impedance control signal and the pull-down impedance control signal that are converted into thermometer codes with extended bit numbers; and a pre-driver unit including multiple pre-drivers that are activated or deactivated by the pull-up impedance control signal and the pull-down impedance control signal to adjust the impedance of devices of the pull-up device and the pull-down device. [Reference numerals] (310) Pre-driver unit; (320) Output driver; (330) Regulator; (340) impedance control signal outputt unit; (350) Decoder