Power supply current monitoring techniques for testing PLLs

The effectiveness of current testing for digital IC´s has led researchers to explore the possibility of extending this concept to testing analog blocks of mixed-signal ICs. Unfortunately, test techniques developed for commonly-studied analog blocks such as op-amps and filters do not apply to non-linear blocks such as phase-locked loops. This paper focuses on investigating the effectiveness of using an operating power supply current monitoring technique to detect potential faults in a phase-locked loop (PLL) circuit