CLOCK MODULATING CIRCUIT FOR COMPENSATING DUTY RATIO AND SPREAD-SPECTRUM CLOCK GENERATOR

摘要

A clock modulation circuit for correcting a duty ratio and a spread-spectrum clock generator having the same are provided to prevent a system error by adjusting the duty ratio as 50:50. A clock modulation circuit for correcting a duty ratio includes a modulation block(200). The modulation block includes first and second inverters(210,220) and a correction unit(250). The first inverter receives a fixed clock(FCLK) and performs reverse-amplification for the fixed clock. The second inverter receives an output signal of the first inverter and performs reverse-amplification for the output signal to generate a modulation clock(MCLK). The correction unit includes first and second correction units(250a,250b). The first correction unit controls an output level of the first inverter. The second correction unit controls an output level of the second inverter.