Switching converter with wide input voltage range and control circuit thereof

A control circuit for a switching converter, comprising:

• a first error amplifying circuit configured to receive an output feedback signal representative of an output voltage of the switching converter and to provide a first error amplifying signal based upon the output feedback signal and an output reference signal;
• a second error amplifying circuit configured to receive the first error amplifying signal and a current sense signal representative of a current flowing through an inductor of the switching converter, and to provide a second error amplifying signal based upon the first error amplifying signal and the current sense signal;
• a control voltage generator having a first input terminal configured to receive the second error amplifying signal and a second input terminal configured to receive a reference voltage, wherein the control voltage generator is configured to provide a control voltage based upon a voltage difference between the second error amplifying signal and the reference voltage;
• and
• a pulse width modulation circuit configured to provide a first pulse width modulation signal and a second pulse width modulation signal based upon an input voltage, the output voltage and the control voltage, wherein the first pulse width modulation signal is used to control a first switch pair of the switching converter for selectively coupling a first terminal of the inductor to the input voltage or a reference ground of the switching converter, and the second pulse width modulation signal is used to control a second switch pair of the switching converter for selectively coupling a second terminal of the inductor to the output voltage or the reference ground.