Patent ID: 7579890

Claim:
A duty detector, comprising: a first amplifier configured to receive a first signal and a complementary first signal, differential-amplify the first signal and the complementary first signal, and output the differential-amplified first signal to an output terminal and the differential-amplified complementary first signal to a complementary output terminal; and an integrator connected to the output terminal and the complementary output terminal of the first amplifier, configured to integrate the differential-amplified first signal and the differential-amplified complementary first signal, and configured to output a duty detection signal, wherein the integrator includes, a second amplifier configured to receive the differential-amplified first signal through a positive input terminal, receive the differential-amplified complementary first signal through a negative input terminal, differential-amplify the received signals, and output the duty detection signal, a third amplifier configured to receive the differential-amplified complementary first signal through a positive input terminal, receive the differential-amplified first signal through a negative input terminal, differential-amplify the received signals, and output a complementary duty detection signal, a first capacitor coupled between the negative input terminal of the second amplifier and an output terminal of the second amplifier, a second capacitor coupled between the negative input terminal of the third amplifier and an output terminal of the third amplifier, a third capacitor coupled to the output terminal of the second amplifier, and a fourth capacitor coupled to the output terminal of the third amplifier.