Industrial Technology Research Institute

Realtek Semiconductor Inc.

Yo-Hao Tu

Chia-Liang (Leon) Lin

Kuo-Hsing Cheng

Yu-Hsiang Chen

An-Ming Lee

Jen-Chieh Liu

Chi-Yang Chang

An apparatus is provided that includes a frequency doubler circuit and a duty cycle adjusting circuit. The frequency doubler circuit includes a multiplexer, a variable delay circuit and a divide-by-2 circuit. The multiplexer selects one of a first and a second clock signals having opposite phases according to a selection signal to generate a frequency doubled clock signal. The variable delay circuit delays the frequency doubled clock signal. The divide-by-2 circuit divides a frequency of the frequency doubled clock signal to generate the selection signal. The duty cycle adjusting circuit includes an average voltage generation circuit and a comparison circuit. The average voltage generation circuit generates an average voltage value of the frequency doubled clock signal. The comparison circuit generates a control signal according to a comparison result of the average voltage value and a reference voltage to control the duty cycle of the frequency doubled clock signal.

Frequency doubling apparatus and method thereof

A crystal-less clock generator (CLCG) and an operation method thereof are provided. The CLCG includes a first oscillation circuit, a second oscillation circuit, and a control circuit. The first oscillation circuit is controlled by a control signal for generating an output clock signal of the CLCG. The second oscillation circuit generates a reference clock signal. The control circuit is coupled to the first oscillation circuit for receiving the output clock signal and coupled to the second oscillation circuit for receiving the reference clock signal. The control circuit is used to generate the control signal for the first oscillation circuit according to the relationship between the output clock signal and the reference clock signal.

Crystal-less clock generator and operation method thereof

Growing community of inventors

Taipei, Taiwan

Yo-Hao Tu