Digital duty cycle correction circuit

摘要

A digital duty cycle correction circuit includes a duty cycle controller and a digital duty control code generator. The duty cycle controller generates first and second output clock signals by compensating duty cycles of first and second input clock signals based on a digital duty control code. The digital duty control code generator generates the digital duty control code based on a frequency value obtained by converting duty cycle information of the first output clock signal and the second output clock signal.

主权项

1. A digital duty cycle correction circuit comprising:
a duty cycle controller configured to generate a first output clock signal and a second output clock signal by compensating a duty cycle of a first input clock signal and a duty cycle of a second input clock signal based on a digital duty control code, the first and second input clock signals being a pair of differential signals, the first and second output clock signals being a pair of differential signals; and a digital duty control code generator configured to generate the digital duty control code based on a frequency value obtained by converting duty cycle information of the first output clock signal and the second output clock signal, wherein the digital duty control code generator comprises:
a monitor configured to generate a first direct current (DC) voltage and a second DC voltage by monitoring the first output clock signal and the second output clock signal;a voltage-frequency converter configured to generate a reference frequency signal, a first frequency signal and a second frequency signal by performing a voltage-frequency conversion on a reference voltage, the first DC voltage and the second DC voltage;a frequency counter configured to generate a reference count value, a first count value and a second count value by counting pulses of the reference frequency signal, pulses of the first frequency signal and pulses of the second frequency signal; anda digital state machine configured to generate the digital duty control code based on the reference count value, the first count value and the second count value.