Design Of A Charge-Pump Phase-Lock-Loop Used For HDMI Transmitter

HDMI which means "High Definition Multimedia Interface" is a new transmitting protocol for digital video. It can support higher data rate and can transmit digital audio/video signals without loss.This work has designed a CPPLL used for the HDMI transmitter. It can multiply the frequency of input signal ranging from 25MHz to 165MHz with 5. And the output signal is used as the trigger pulse when serial data turn into parallel data.In this paper, the basic principle of PLL is analyzed, and the structure of the whole system is chosen. Every part of PLL is discussed in detail and carefully designed. The simulation results show the design is qualified. At last there are some advices on the layout.High speed, low supply voltage and wide frequency range are difficult problems in this design. In order to overcome those difficulties, the differential cross-coupled VCO with two stages is adopted which can cover the required frequency range and has good linearity by carefully design. The TSPC D flip-flop is used in the frequency divider in order to reach high speed. In the charge pump a unit gain opamp is applied to reduce the effect of charge sharing.The TSMC 0.18μm CMOS process is used in this work. The supply voltage is 1.8V. The simulation results of both the behavior level and the transistor level show that the PLL meet the requirement of the HDMI transmitter.