Implementation of Low Power, Wide Range ADPLL for Video Applications

Sammanfattning: Phase locked loop (PLLs) are the keystone for the electronic as well as for the communication circuits. Without any exaggeration, PLLs are found almost in every electronic and communication devices. Countless research has been performed, for the modification and enhancement of the PLLs circuit. While, due to the numerous advantage of the digital circuitry, the recent research is focusing on the all digital implementation of the PLLs. Therefore, it was competitive to touch with burning research. Low power and wide range all digital phase locked loop (ADPLL), for video applications is presented. ADPLL has an operating input frequency between 10kHz to 150 kHz and output frequency between 10 MHz to 300 MHz. The phase frequency detector (PFD) is based on D-flip flops, having two output error and direction signal. The traditional charge pump (CP) is replaced by time-to-digital converters (TDC) and analog low pass filter (LPF) by digital low pass filter (digital-LPF). For completely digital architecture, voltage controlled oscillator (VCO) is replaced by the digitally controlled oscillator (DCO). In DCO, eleven bits are dedicated for controlling bits, two bits for biasing and one bit for enable the DCO. The designed steps for ADPLL were almost similar to the designed steps of a second order analog PLL. The ADPLL is implemented on a CMOS 65-nm technology.