APPARATUS AND METHOD FOR RECOVERING BURST-MODE PULSE WIDTH MODULATION (PWM) AND NON-RETURN-TO-ZERO (NRZ) DATA

摘要

A gated voltage controlled oscillator has four identically structured delay cells, each of the delay cells having the same output load by connecting to the same number of inputs of other ones of the delay cells. Optionally a four phase sampling clock selects from the delay cell output and samples, at a four phase sampler, an input signal. Optionally an edge detector synchronizes the phase of the gated voltage controlled oscillator to coincide with NRZ bits. Optionally a variable sampling rate selects different phases from the delay cells to selectively sample NRZ bits at a lower rate. Optionally, a pulse width modulation (PWM) mode synchronizes a phase of the sampling clock to sample PWM symbols and recover encoded bits.