Patent ID: 6472946
Filing Date: 2002-10-29
Classification: G09G,H03K

Abstract:
A modulation circuit for modulating an input data on a pulse width and a pulse amplitude in response to the value of the input data and generating a pulse signal at a predetermined period, comprisinga phase data generating circuit for generating a phase data whose value is varied in response to a phase in the period; a data comparison circuit for setting a control signal at a first level at the beginning of every period, comparing the phase data and the input data, and setting the control signal at a second level when the phase data and the input data coincide; and a pulse signal generating circuit for setting the level of the pulse signal at a reference level at the beginning of every period, changing the level of the pulse signal in response to the phase data when the control signal is at the first level, setting the level of the pulse signal at the reference level when the control signal is changed to the second level, and outputting the resultant pulse signal.