SIGNAL CONVERSION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a signal conversion circuit which doesn't require large-capacity elements and is easily made into an integrated circuit. SOLUTION: A data signal corresponding to a high level period of a PWM signal is generated in a first counter part 107, and a data signal corresponding to a low level period of the PWM signal is generated in a second counter part 111. A data signal corresponding to the number of pulses in one cycle of the PWM signal is generated from two data signals by an adder 114, and furthermore, a current signal SPTwhich is reduced for a longer cycle and is increased for a shorter cycle is generated in a first D/A converter circuit 116 and a current source circuit on the output side of the circuit 116. When a voltage signal SDCis generated from the data signal corresponding to the high level period by a second D/A converter circuit 123, the magnitude of the voltage signal SDCis corrected by the current signal SPTto be a magnitude which is proportional to the high level period with a positive coefficient and is proportional to the cycle with a negative coefficient. COPYRIGHT: (C)2008,JPO&INPIT