DC-DC converter with pull-up or pull-down current and associated control method

A DC-DC converter for converting an input voltage to an output voltage at an output node, comprising:

• an inductor having a first node and a second node, with an inductor current flowing through the inductor;
• a switch module, for selectively connecting the input voltage or a ground voltage to the first node of the inductor according to a driving signal;
• a pull-down circuit, coupled to the output node of the DC-DC converter, for sinking a current from the output node of the DC-DC converter;
• wherein the current is a multiple of the inductor current.

A DC-DC converter for converting an input voltage to an output voltage at an output node, comprising:

• an inductor having a first node and a second node, with an inductor current flowing through the inductor;
• a switch module, for selectively connecting the input voltage or a ground voltage to the first node of the inductor according to a driving signal;
• a pull-up circuit, coupled to the output node of the DC-DC converter, for providing a current to the output node of the DC-DC converter, wherein the current is a multiple of the inductor current;
• and the pull-up circuit comprises:
• a transistor comprising a gate electrode, a first electrode and a second electrode, where the first electrode is coupled to a supply voltage, and the second electrode is coupled to the output node of the DC-DC converter;
• and
• an operational amplifier, wherein a first input terminal of the operational amplifier is coupled to the first electrode of the transistor, a second input terminal of the operational amplifier receives a reference signal, and an output terminal of the operational amplifier is coupled to the gate electrode of the transistor, and the reference signal is generated based on the inductor current.