Patent ID: 7924068

Claim:
An automatic adjustment circuit for automatically adjusting frequency characteristics, comprising: a replica made of a circuit block, or a portion thereof, of a circuit to be adjusted; and an integrating circuit for using any of an external reference signal or a plurality of external reference signals and an output signal or a plurality of output signals from said replica to which said reference signal or reference signals are input, as a clock signal and input signals, and integrating said input signal in synchronism with said clock signal, wherein said integrating circuit comprises: first and second charge pumps for discharging or drawing currents through output terminals thereof depending on high or low levels of signals input thereto; first and second switch circuits for short-circuiting or opening input and output terminals thereof depending on high or low levels of signals input to switching terminals thereof; an inverting circuit; and a capacitor; wherein said output terminal of said first charge pump, said output terminal of said second charge pump, and said input terminal of said first switch circuit are connected to each other; said capacitor and the input terminal of said second switch circuit are connected parallel to the output terminal of said first switch circuit; said inverting circuit has an output terminal connected to the switching terminal of said second switch circuit; and said inverting circuit has an input terminal connected to the switching terminal of said first switch circuit.