Built-in ripple injection circuit and control chip

A control chip, comprising an built-in ripple injection circuit integrated within the control chip and comprising:

• a feedback circuit comprising:
• a first terminal for receiving an output voltage;
• a grounded second terminal;
• and an output terminal for outputting a divided feedback voltage;
• an operational amplifier comprising a first input terminal, which is connected to the output terminal of the feedback circuit and configured to receive the divided feedback voltage;
• a first capacitor comprising:
• a first terminal connected to the first terminal of the feedback circuit;
• and a second terminal, which is connected to an output terminal of the operational amplifier and configured to couple high-frequency ripple in the output voltage to the output terminal of the operational amplifier;
• and
• a source follower comprising:
• a first terminal connected to the output terminal of the operational amplifier;
• a second terminal connected to the first terminal of the first capacitor;
• and a third terminal, which is connected to a second input terminal of the operational amplifier and configured to output a feedback voltage, and
• the control chip further comprising another operational amplifier,
• the other operational amplifier comprising:
• a first input terminal for receiving a reference voltage;
• a second input terminal, which is coupled to the third terminal of the source follower and configured to receive the feedback voltage;
• and an output terminal for outputting a control signal.