DC-DC converter with pull-up and pull-down currents based on 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, wherein the second node is coupled to the output node of the DC-DC converter;
• 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 selectively providing a first current to the output node of the DC-DC converter;
• and
• a pull-down circuit, coupled to the output node of the DC-DC converter, for selectively sinking a second current from the output node of the DC-DC converter;
• wherein at least one of the first current provided by the pull-up circuit and the second current sunk by the pull-down circuit is determined based on an inductor current flowing through the inductor;
• wherein the pull-up circuit comprises:
• a first 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
• a first operational amplifier, wherein a first input terminal of the first operational amplifier is coupled to the first electrode of the first transistor, a second input terminal of the first operational amplifier receives a first reference signal, and an output terminal of the first operational amplifier is coupled to the gate electrode of the first transistor, and the first reference signal is generated based on the inductor current.

A method for controlling a DC-DC converter, wherein the DC-DC converter comprises an inductor and a switch module, the inductor has a first node and a second node, the second node is coupled to an output node of the DC-DC converter, and the switch module selectively connects the input voltage or a ground voltage to the first node of the inductor according to a driving signal;

• and the method comprises:
• selectively providing a first current to the output node of the DC-DC converter;
• and
• selectively sinking a second current from the output node of the DC-DC converter;
• wherein at least one of the first current and the second current are determined based on an inductor current flowing through the inductor, the first current or the second current has a positive relationship with the inductor current, and the first current or the second current is a multiple of the inductor current.