A 10-Phase 270MHz 5000ppm spread spectrum clock generator

This paper presents the spread spectrum clock generator which reduces EMI. The proposed spread spectrum clock generator consists of a basic PLL, a voltage-controlled oscillator (VCO) controller, the frequency modulator, and voltage reference. The output clock frequency of the proposed clock generator is 10-phase 270 MHz and 162 MHz frequency is also supported. A phase noise of the proposed clock generator is -67.5 dBc/Hz at 45 kHz in 270 MHz mode and -72 dBc/Hz at 30 kHz in 162 MHz mode. 8.75 dBm of the peak reduction and 0.5% of spread ratio achieved.