Control circuit and device with edge comparison for switching circuit

A control circuit for a switching circuit, which is used to control the switching circuit operated under continuous conduction mode, wherein the switching circuit comprises a first switch and transforms an input voltage into an output voltage for driving loads by turning the first switch on and off, comprising:

• a timing module configured to start measuring time at a rising edge of a turn-on signal of the first switch;
• a regulation module being connected with the timing module and configured to reduce a turn-on time or a turn-off time of the first switch for fixing a frequency of the switching circuit when a first measured time is reached and the rising edge in a next cycle of the turn-on signal has not arrived, and to increase the turn-on time or the turn-off time of the first switch for fixing the frequency of the switching circuit when the rising edge in the next cycle of the turn-on signal arrives but the first measured time is not reached,
• wherein the first measured time and a predetermined time of a switching cycle of the turn-on signal are the same within a certain error range,
• wherein the timing module comprises a second switch, a second capacitor, a second voltage comparator and a second current source,
• a control terminal of the second switch receives the turn-on signal of the first switch, a first terminal of the second switch is grounded, a second node is a node connected with a second terminal of the second switch;
• the second node is coupled with the second current source, a first input terminal of the second voltage comparator and a first terminal of the second capacitor, respectively, a second terminal of the second capacitor is grounded, a voltage of a second input terminal of the second voltage comparator is a first reference voltage, wherein the first reference voltage is the same with a voltage of the second node at the time when the first measured time is equal to the predetermined time of a switching cycle of the turn-on signal of the first switch,
• wherein the regulation module comprises an edge comparator which has a first input terminal connected with an output terminal of the second voltage comparator to receive said output signal and a second input terminal for receiving the turn-on signal of the first switch.