Clock generator circuit, signal multiplexing circuit, optical transmitter, and clock generation method

Abstract

For the purpose of achieving multiplexing of data signals for the channels of more than four in number in the generating of a frequency-divided clock signal using toggle flip-flop circuits (TFF), while avoiding any possible phase shift relationship between generated frequency-divided clock signals attributed to the indefinite initial state posing the inherent problem of the TFF, there is provided a clock generator circuit comprising a plurality of toggle flip-flop circuits connected in series, capable of outputting a pair of frequency-divided clock signals with different phases; and a delay circuit connected to the toggle flip-flop circuit, capable of outputting a clock signal with a phase shifted with respect to the phases of the pair of frequency-divided clock signal phases by delaying either one or both of the pair of frequency-divided clock signals being outputted from the toggle flip-flop circuits.