The purpose of a phase locked loop (PLL) is to generate a frequency and phase-locked output oscillation signal. To achieve this goal, prior art essentially functioned ...

…which would take a pulse-width-modulated waveform at any frequency, and produce a signal with exactly the same mark/space ratio, but at a nominated frequency (see ‘Why might this be useful?’ below).

Radiation-hardened phase-locked loop (PLL) circuits represent a critical advancement in safeguarding electronic systems against the deleterious effects of ionising radiation. These circuits are ...