Embodiments of the present invention describe methods and apparatuses for detecting signal loss in circuits such as a phase-locked loop. During a first phase of operation, the isolation device is activated and isolates the integrator from the second charge storage device, and the input charge received on the input terminal of the integrator is stored on the first charge storage device. The PCD material comprises 15 percent by volume or less diamond grains sized 20 micrometers or less.