A frequency multiplier.

摘要

A frequency multiplier of a character generating circuit is disclosed, wherein two frequency doublers which include a phase inverter (30) for inverting a phase by inputting a color sub-carrier signal, a 90 DEG phase shifter (40) for shifting a phase by 90 DEG by inputting the color sub-carrier signal, and an analog multiplier (50) for outputting a doubled signal that multiplies the output of the phase inverter by the output of the 90 DEG phase shifter, are connected in series so as to generate a clock to create a blue screen, to thereby reduce product cost and noise.