Patent ID: 9608519
Date: 2017-03-28
CPC Classifications: H02M

Claim:
1. A switching converter with adaptive OFF time control, comprising: a power stage comprising a main switch, the power stage being configured to convert an input voltage to an output voltage; a current sense circuit coupled to the power stage to generate a current sense signal indicative of the current flowing through the main switch; an error amplifier having a first input terminal configured to receive a feedback signal indicative of the output voltage, a second input terminal configured to receive a first reference signal, and an output terminal configured to generate a compensation signal based on the feedback signal and the first reference signal; a PWM comparator having a first input terminal coupled to the current sense circuit to receive the current sense signal, a second input terminal coupled to the output terminal of the error amplifier to receive the compensation signal, and an output terminal configured to generate a PWM signal based on the current sense signal and the compensation signal; an OFF time controller having a first input terminal configured to receive the input voltage, a second input terminal configured to receive the output voltage, and an output terminal configured to generate an OFF time control signal based on the input voltage and the output voltage to control the OFF time of the main switch; and a logic circuit having a first input terminal coupled to the output terminal of the PWM comparator to receive the PWM signal, a second input terminal coupled to the output terminal of the OFF time controller to receive the OFF time control signal, and an output terminal configured to output a switching signal based on the PWM signal and the OFF time control signal to control the main switch.