System and method to detect synchronous switching regulator light load
AssigneeTexas Instruments Incorporated
InventorsAriel S. Bentolila, Sisan Shen
Life of this patent
Estimating the term…
Abstract
An efficient and practical system and method to determine when a switching DC-DC regulator is under a light load condition. The light load condition is determined by monitoring the switch node voltage to detect a zero-crossing voltage that is load dependent and occurs when the average output current minus half the switching current at the switch node is less than or equal to zero.
Claims11
A switching regulator light load detection system comprising:
- a MOSFET synchronous DC-DC switching regulator system having at least one NMOS FET and at least one PMOS FET connected in binary push-pull configuration and further having a common switch node;
- an inductor connected to the common switch node;
- and
- a positive going zero-crossing voltage detector connected to the common switch node.
A switching regulator light load detection system comprising:
- a MOSFET synchronous DC-DC switching regulator system having at least one NMOS FET and at least one PMOS FET connected in binary push-pull configuration and further having a common switch node;
- an energy storage device connected to the common switch node;
- and
- means for detecting a zero-crossing switch node voltage and generating a switching regulator output, light loading operating point in response therefrom.
A method of detecting a switching regulator light load condition, the method comprising the steps off:
- a) providing a switching regulator light load detection system comprising:
- a MOSFET synchronous DC-DC switching regulator system having at least one NMOS FET and at least one PMOS FET connected in binary push-pull configuration and further having a common switch node;
- an inductor connected to the common switch node;
- a positive going zero-crossing voltage detector connected to the common switch node;
- and
- a pulse detector connected to the positive going zero-crossing voltage detector;
- b) detecting a change in common switch node voltage;
- and
- c) generating a switching regulator control output signal, light loading operating point indicator when a positive going switch node voltage crosses zero volts.
A method of detecting a switching regulator light load condition, the method comprising the steps of:
- a) providing a switching regulator light load detection system comprising:
- a MOSFET synchronous DC-DC switching regulator system having at least one NMOS FET and at least one PMOS FET connected in binary push-pull configuration and further having a common switch node;
- an inductor connected to the common switch node;
- and
- a pulse detector connected to this common switch node, the pulse detector configured to detect a switch node current;
- b) detecting a change in common switch node current during operation of the switching regulator;
- and
- c) generating a switching regulator control output, light loading operating point indication when an average output current associated with an output load current minus half a switching current associated with a peak-to-peak switching current becomes no less than zero during a discontinuous operating phase of the switching regulator.
A switching regulator light load detection system comprising:
- a MOSFET synchronous DC-DC switching regulator system having at least one NMOS FET and at least one PMOS FET connected in binary push-pull configuration and further having a common switch node;
- a voltage comparator connected to the common switch node and configured to detect a zero-crossing voltage at the common switch node and generate a signal therefrom;
- a signal detection system configured to generate a switching regulator output, light loading operating point indicator in response to the signal generated by the voltage comparator;
- and
- an inductor connected to the common switch node, wherein the inductor is configured to accommodate a predetermined load detection trip range associated with the switching regulator output, light loading operating point.
Dependencies are inferred from the claim text.