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US 9,178,420 B1Granted
Inductive bypass, storage and release improves buck response
AssigneeMaxim Integrated Products, Inc.
InventorStephen Hawley
Life of this patent
Estimating the term…
Abstract
Various embodiments of the invention improve the dynamic response and output voltage accuracy in buck DC-DC converters. In certain embodiments, power efficiency is improved by storing and recycling energy that is otherwise lost during successive load transient events.
Claims18
A DC-DC converter circuit to generate an output voltage for a system load, the DC-DC converter circuit comprising:
- an inductive element coupled between an input and an output of the DC-DC converter circuit;
- first and second switches coupled to the inductive element, the switches selectively turn ON and OFF in a predetermined sequence;
- a third switch coupled in parallel to the inductive element;
- and
- a controller coupled to the first, the second, and the third switches, the controller comprises circuitry to generate control signals that selectively activate the third switch in response to the controller detecting a polarity of a load transient event to maintain a circulating current between the third switch and the inductive element until operating the third switch in a linear voltage regulation mode to adjust a current supplied through the third switch.
2 more elements
A DC-DC converter system comprising:
- a voltage source that provides a voltage signal;
- a DC-DC converter circuit, coupled to the voltage source, the DC-DC converter circuit comprises:
- an inductive element coupled between an input and an output of the DC-DC converter circuit, the inductive element stores and releases energy in relation to DC power at the output of the DC-DC converter circuit;
- a switch coupled in parallel to the inductive element, the switch configured to operate as a variable resistor in a linear voltage mode;
- and
- a controller coupled to a plurality of switches, the controller generates control signals hat selectively activate the switch in response to the controller detecting a polarity of one or more of the load transient events to maintain a circulating current through the inductive element immediately prior to switching to the linear voltage mode.
3 more elements
A method to control transient responses of a DC-DC buck voltage converter, the method comprising:
- monitoring a transient load condition at an output of the buck voltage converter;
- determining from a polarity of the transient load condition whether an output voltage exceeds a predetermined threshold voltage;
- in response to the predetermined threshold voltage having a first polarity, activating a first switch operating as a variable resistor to maintain a circulating current to pass through the first switch and through at least one energy storage element coupled in parallel with the first switch;
- activating a plurality of switches that switch in a predetermined sequence in relation to an energy stored in the energy storage element;
- in response to the predetermined threshold voltage having a second polarity, activating the first switch to allow the current to circulate between the switch and the at least one energy storage element immediately prior to activating the first switch operating as a variable resistor and
- in response to a transient change, opening the first switch to release energy to a system load.
3 more elements
Dependencies are inferred from the claim text.