CR-CORRECTING CONSTANT-CURRENT CIRCUIT

PROBLEM TO BE SOLVED: To reduce the element area by outputting a constant current from a constant-current source circuit in a feedback loop composed of the constant- current source circuit which inputs the output voltage of a negative feedback amplifier, a saw-tooth wave generating circuit, and a peak holding circuit. SOLUTION: The output voltage of the negative feedback amplifier 36 is supplied to the constant-current circuit 37 to generate the constant current, which is supplied to the saw-tooth wave generating circuit 38. The saw-tooth wave generating circuit 38 receives a clock signal 3 and supplies charging currents IP4D and IP5D from the constant current circuits 37 to 2nd and 3rd internal capacitors 20 and 22 to generate and send two saw-tooth waves A and B to the peak holding circuit 40. The peak holding circuit 40 puts the two saw-tooth waves A and B together to feed the peak-held signal back to the inverted input terminal of the negative feedback amplifier 36, which is made to compare it with a reference voltage 2. The feedback loop controls the charging currents IP4D and IP5D so that the output voltage of the peak holding circuit 40 is as high as the reference voltage 2, thereby regarding corresponding constant currents as 1st and 2nd outputs 34 and 35.