Control architecture with improved transient response

摘要

A power supply system includes a power source; a load device configured to receive power from the power source; and a power interface device coupled to the power source and the load device and configured to change a first voltage provided by the power source to a second voltage for operating the load device. The power interface device include a main switching converter configured to operate at a first switching frequency and source low frequency current to the load device and an auxiliary switching converter coupled in parallel with the main switching converter and configured to operate at a second and different switching frequency and source fast transient high frequency current to the load device.

主权项

1. A power interface device comprising:
a main switching converter configured to receive a first voltage at an input terminal and to output a second and different voltage at an output terminal, the main switching converter including a first main switch, a second main switch, and a main inductor, wherein the first main switch at one end is coupled to the input terminal and at another end is coupled to a main node, the second main switch at one end is coupled to the main node and at another end is coupled to a ground terminal, and the main inductor at one end is coupled to the main node and at another end is coupled to the output terminal; an auxiliary switching converter coupled in parallel with the main switching converter and configured to receive the first voltage at the input terminal and to output the second voltage at the output terminal, the auxiliary switching converter including a first auxiliary switch, a second auxiliary switch, and an auxiliary inductor, wherein the first auxiliary switch at one end is coupled to the input terminal and at another end is coupled to an auxiliary node, the second auxiliary switch at one end is coupled to the auxiliary node and at another end is coupled to a ground terminal, and the auxiliary inductor at one end is coupled to the auxiliary node and at another end is coupled to the output terminal; and an auxiliary control loop circuit at one end coupled to the output terminal and at another end coupled to the auxiliary switching converter, the auxiliary control loop circuit configured to detect a transient at the output terminal and responsive to the transient issue an auxiliary control signal for driving the auxiliary switching converter to output fast transient high frequency current to the output terminal, wherein: the auxiliary control loop circuit is configured to prevent a lower frequency component of a transient signal associated with the transient from entering the auxiliary switching converter by using a resistor and an adder circuit, the resistor is coupled at one end to the auxiliary inductor and at another end to the adder circuit coupled to the output terminal, and the auxiliary switching converter is configured to operate at an auxiliary switching frequency different from a main switching frequency of the main switching converter.