Switched mode power supply with a bypass path for shunting current

Patent metadata

Field	Value
Publication number	US-9385605-B2
Application number	US-201113699872-A
Country	US
Kind code	B2
Filing date	May 24, 2011
Priority date	May 24, 2010
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A switching stage is provided that generally includes multiple switching paths for routing a signal. For example, the switching stage may include a first switching path having at least one switching element for selectively connecting an input of the switching stage to an output of the switching stage and a second switching path having at least one switching element for selectively connecting the input of the switching stage to the output of the switching staged. In certain aspects, the first and second switching paths are controlled such that a signal is selectively routed from the input of the switching stage to the output of the switching stage via the first and second switching paths in dependence on the current of the signal to be routed.

First claim

What is claimed is:

1. A switching stage comprising:
a first switching path having at least one switching element for selectively connecting an input of the switching stage to an output of the switching stage; and
a second switching path having at least one switching element for selectively connecting the input of the switching stage to the output of the switching stage,
wherein the first and second switching paths are controlled such that a signal is selectively routed from the input of the switching stage to the output of the switching stage via the first and second switching paths in dependence on the current of the signal to be routed,
wherein the at least one switching element of the second switching path is selectively connected to route the signal from the input to the output such that with the at least one switching element of the second switching path in a first state, the current in the second path rises until a first current threshold level is reached, responsive to which condition the at least one switching element of the second switching path is switched to a second state, and
wherein in the second state the current in the second path falls until a second current threshold level is reached, responsive to which condition the at least one switching element of the second switching path is switched to the first state, wherein there is provided a further switching element in the second switching path arranged to selectively connect a first terminal of a first inductor to a higher voltage level, wherein the connection to the higher voltage level is enabled responsive to the current in the second switching path falling to the second threshold level when the at least one switching element of the second switching path is in the first state.

2. The switching stage of claim 1 wherein the at least one switching element of the first switching path is configured to handle a smaller current than the at least one switching element of the second switching path, and wherein the size of the at least one switching element of the first switching path is smaller than the size of the at least one switching element of the second switching path.

3. The switching stage of claim 1 , wherein the at least one switching element of the second switching path is selectively connected to route the signal from the input to the output such that the current in the second path is maintained within a predetermined range.

4. The switching stage of claim 1 wherein the higher voltage level is provided by a signal line of the first switching path.

5. The switching stage of claim 1 , wherein the further switching element connects the first terminal of the first inductor to the higher voltage level until the current in the second switching path rises to the first threshold level.

6. The switching stage of claim 1 , wherein the further switching element is arranged to switch the first terminal of the first inductor to successively higher voltages if the current falls to the first threshold level whilst connected to a given voltage level.

7. The switching stage of claim 1 , wherein the further switching element is arranged to switch the first terminal of the first inductor to successively lower voltages if the current rises to the second threshold level whilst connected to a given voltage level.

8. The switching stage of claim 1 , wherein:
the at least one switching element of the second switching path comprises a first switch connected between a voltage source and a first terminal of the first inductor and a second switch connected between the first terminal of the first inductor and electrical ground,
a second terminal of the first inductor is connected to the output of the switching stage,
in the first state the first switch connects the first terminal of the first inductor to the voltage source, and
in the second state the second switch connects the first terminal of the first inductor to electrical ground.

9. A switching stage comprising:
a first switching path having at least one switching element for selectively connecting an input of the switching stage to an output of the switching stage; and
a second switching path having at least one switching element for selectively connecting the input of the switching stage to the output of the switching stage,
wherein the first and second switching paths are controlled such that a signal is selectively routed from the input of the switching stage to the output of the switching stage via the first and second switching paths in dependence on the current of the signal to be routed,
wherein the at least one switching element of the second switching path is selectively connected to route the signal from the input to the output such that the current in the second path is maintained within a predetermined current range, and
wherein the predetermined current range includes an upper and a lower limit determined in dependence on a target average value of the current in the first switching path, wherein the lower limit is determined in dependence on a difference between a sensed value of the current in the first switching path and the target average value of the current and wherein the upper limit is determined in dependence on a constant offset added to the lower limit.

10. The switching stage of claim 1 , wherein the at least one switching element of the first switching path includes at least one switch array for connecting the input with one of a plurality of outputs.

11. The switching stage of claim 1 , wherein the at least one switching element of the first switching path includes at least one switch array for connecting one of a plurality of inputs with the output.

12. The switching stage of claim 1 , wherein the at least one switching element of the first switching path includes a first switch array for connecting an input of the first switch array to one of a plurality of intermediate signal lines, and a second switch array for connecting one of the plurality of intermediate signal lines to an output of the second switch array.

13. The switching stage of claim 12 , further comprising a second inductor connected between a voltage source and the input of the first switch array, and a third inductor connected between the output of the second switch array and the output of the switching stage.

14. The switching stage of claim 13 , further comprising a plurality of capacitors, each capacitor being connected between a respective intermediate signal line and electrical ground.

15. The switching stage of claim 14 , further comprising a capacitor connected between the output of the switching stage and electrical ground, and the first inductor connected between the at least one switching element of the second switching path and the output of the switching stage.

16. A voltage converter including a switching stage according to claim 12 , wherein the first switch array of the first switching path is controlled to generate a plurality of voltage supply levels on the intermediate signal lines, and the second switch array of the first switching path is controlled to select one of the generated voltage supply levels as a voltage supply.

17. The voltage converter of claim 16 wherein the second switch array is controlled to track the envelope of a reference signal, such that an output voltage is developed at the output of the switching stage which corresponds to a desired voltage level.

Assignees

• Wilson Martin Paul
• Snaptrack Inc

Inventors

• Wilson Martin Paul

Classifications

• H02M3/1584 Primary

  with a plurality of power processing stages connected in parallel · CPC title

• H02M3/1582 Primary

  Buck-boost converters (H02M3/1584 takes precedence) · CPC title

• G05F1/56

  using semiconductor devices in series with the load as final control devices (G05F1/461 takes precedence) · CPC title

• H03F2200/78

  A comparator being used in a controlling circuit of an amplifier · CPC title

• H03F1/0227

  using supply converters · CPC title