Stability Consideration of the Voltage Switched Charge-pump Phase Locked Loop using Linear Approach

• DOI: 10.19026/rjaset.13.2939
• Publication Date: 2016-10-10T19:16:11Z
• Authors: Ehsan Ali; Abdul Sattar Sand; Farida Memon; Ghulam Mustafa Bhuto; Nasreen Nizamani
• Keywords: PLL multibit; Operating point; Transient (computer programming)

The aim of this study to provide possible criteria consider the stability Voltage Switched Charge-Pump Pump Phase Locked Loop (VSCP-PLL). Stability conventional CP-PLL architecture is often determined by Gardner's plane, when PLL system locked and near fixed point. In latest work it has been shown that, criterion not conservative enough considering initial condition far from However, based on operating with a Current Charge (CSCP), which provides an ideal pump current during switching states. Nevertheless, (VSCP) used in many commercially available circuits (like 4046 family). VSCP offers design simplicity but generates peculiar effect related non-constant flowing through electrical load Filter (LF) w. r. t. point (average input voltage) Controlled Oscillator (VCO). This non-linearity may complicate characteristics making difficult analyze system, since there no any particular developed VSCP-PLL. study, procedure proposed for designers apply similar CSCPPLL simulations are performed using efficient discrete time Event-Driven (ED) model. observed conditions simulating transient domain VSCP-PLL Gardner’s plane symmetrical asymmetrical current.