Place 2.0 — An interactive program for PLL analysis and design

Phase Locked Loop Analysis and Circuit Emulation (PLACE) is an interactive program to assist in the design of Phase Locked Loop (PLL) systems. Written in C language, PLACE computes the loop filter components (up to active third-order filters); performs a stability analysis (finding the phase margin and damping ratio); and calculates the lockup time, hold range, and capture range. PLACE computes the PLL output jitter response due to incoming reference signal jitter, output jitter due to reference leakage through the phase detector, and output jitter response due to phase noise of the PLL components. The open and closed loop gain and phase, as well as jitter response, is plotted. Additional features found in PLACE 2.0 are frequency and magnitude of jitter peaking; a sensitivity analysis, which computes changes in loop performance as a function of component variation; and an interactive routine to help the designer optimize PLL performance. Currently residing on Digital Equipment Corporation's VAX-11/780, AT&T 3B20, and IBM System/370 processors, PLACE is presently available at most AT&T Bell Laboratories locations. This paper illustrates the capabilities of PLACE, shows several examples, and discusses the required calculations.