Sigma, delta and sigma-delta DC/DC converters for wide input and output voltage ranges
A DC/DC converter may be formed out of the combination of a first converter that is optimized to transfer energy from a voltage source to a load, and a second converter that receives a control signal derived from the load voltage to regulate the load voltage. The DC/DC converter may be configured as a sigma converter, a delta converter, or a sigma-delta converter. The mode of operation being selected according to the source voltage or the load voltage, either of which may vary over a wide range.
1. A converter receiving a source voltage from a voltage source and providing an output voltage across a load, the converter comprising:
a first DC/DC converter having an input port and first and second output ports; and
a second DC/DC converter having an input port and an output port and receiving a control signal derived from the output voltage; and
wherein (i) the input ports of the first and the second DC/DC converters are connected in series across the voltage source, configured such that the voltage across the input port of the first DC/DC converter is less than the source voltage; (ii) the first output port of the first DC/DC converter providing the output voltage; (iii) the second output port of the first DC/DC converter and the output port of the second DC/DC converter are connected in parallel, and (iv) the second DC/DC converter regulates the output voltage based on the control signal.
2. The converter of claim 1 , wherein the second DC/DC converter comprises a boost converter.
3. The converter of claim 2 , wherein the boost converter is non-isolated.
4. The converter of claim 2 , wherein the first DC/DC converter is isolated by a transformer.
5. The converter of claim 1 , wherein the first DC/DC converter comprises LLC resonant converter.
6. The converter of claim 1 , wherein the first DC/DC converter further comprises a plurality of switches organized in a full-bridge configuration.
7. A converter receiving a source voltage from a voltage source and providing an output voltage across a load, the converter comprising:
a first DC/DC converter having an input port receiving the source voltage across the voltage source and an output port; and
a second DC/DC converter having an input port and an output port and receiving a control signal derived from the output voltage; and
wherein (i) the output ports of the first and the second DC/DC converters are connected in series to provide the output voltage across the load, configured such that the voltage across the output port of the first DC/DC converter is less than the load voltage; and (ii) the second DC/DC converter regulates the output voltage based on the control signal.
8. The converter of claim 7 , wherein the input ports of the first and the second DC/DC converters are connected in parallel, each receiving the source voltage.
9. The converter of claim 8 , wherein the second DC/DC converter comprises a flyback converter.
10. The converter of claim 7 , wherein the input port of the second DC/DC converter and the output port of the first DC/DC converter are connected in parallel.
11. The converter of claim 10 , wherein the second DC/DC converter comprises a buck-boost converter.
12. The converter of claim 7 , wherein the first DC/DC converter further comprises a second output port, and wherein the input port of the second DC/DC converter and the second output port of the first DC/DC converter are connected in parallel.
13. The converter of claim 12 , wherein the first DC/DC converter comprises an isolating transformer.
14. The converter of claim 12 , wherein the second DC/DC converter comprises a buck converter.
15. The converter of claim 14 , wherein the buck converter is non-isolated.
16. The converter of claim 7 , further comprising a second voltage source and wherein the input port of the second DC/DC converter is connected across the second voltage source.
17. The converter of claim 16 , wherein the first DC/DC converter comprises an isolated DC/DC converter.
18. The converter of claim 7 , wherein the first DC/DC converter comprises an LLC resonant converter.
19. The converter of claim 7 , wherein the first DC/DC converter further comprises a plurality of switches organized in a full-bridge configuration.
20. The converter of claim 7 , wherein the first DC/DC converter further comprises an isolating transformer.
21. A converter receiving a source voltage from a voltage source and providing an output voltage across a load, the converter comprising:
a first DC/DC converter having an input port and an output port, the output port being connected across the load; and
a second DC/DC converter having an input port and an output port and receiving a control signal derived from the output voltage; and
wherein (i) the input port of the first DC/DC converter and the output port of the second DC/DC converter are connected in series across the voltage source, configured such that the voltage across the input port of the first DC/DC converter is greater than the source voltage; (ii) the second DC/DC converter regulates the output voltage based on the control signal and (iii) the voltage source and the first DC/DC converter are referenced to a common ground voltage.
22. The converter of claim 21 , wherein the first DC/DC converter comprises an LLC resonant converter.
23. The converter of claim 21 , wherein the input port of the first DC/DC converter further comprises a plurality of switches organized in a full-bridge configuration.
24. The converter of claim 21 , wherein the first DC/DC converter comprises an isolating transformer.
25. The converter of claim 21 , wherein the second DC/DC converter comprises a buck-boost converter.
26. The converter of claim 25 , wherein the buck-boost converter is non-isolated.
27. The converter of claim 21 , wherein the first DC/DC converter further comprises a second output and wherein the second output port of the first DC/DC converter and the input port of the second DC/DC converter are connected in parallel.
28. The converter of claim 21 , wherein the input port of the second DC/DC converter is connected across the voltage source.
29. The converter of claim 21 , wherein the input ports of the first and the second DC/DC converters are connected in parallel.
30. The converter of claim 29 , wherein the second DC/DC converter comprises a buck converter.
31. The converter of claim 30 , wherein the second DC/DC converter comprises a flyback converter.
32. The converter of claim 31 , wherein the second DC/DC converter is non-isolated.
33. The converter of claim 21 , wherein the input port of the second DC/DC converter is connected across a second voltage source.
34. The converter of claim 33 , wherein the second DC/DC converter is non-isolated.
35. A converter receiving a source voltage from a voltage source and providing an output voltage across a load, the converter comprising:
a first DC/DC converter having an input port and an output port; and
a second DC/DC converter having a first input/output port and a second input/output port, wherein the second DC/DC converter is bidirectional and receives a control signal that is derived from the output voltage; and
wherein (i) the input port of the first DC/DC converter and the first input/output port of the second DC/DC converter are connected in series across the voltage source; and (ii) only the second DC/DC converter regulates the output voltage based on the control signal.
36. The converter of claim 35 , wherein the first DC/DC converter comprises an LLC resonant converter.
37. The converter of claim 35 , wherein the first DC/DC converter further comprises a plurality of switches organized in a full-bridge configuration.
38. The converter of claim 35 , wherein the first DC/DC converter comprises an isolating transformer.
39. The converter of claim 35 , wherein the second DC/DC converter further comprises one or more switches for configuring the converter to operate with either a voltage across the input port of the first DC/DC converter being less than the source voltage, or the voltage across the input port of the first DC/DC converter being greater than the source voltage.
40. The converter of claim 35 , wherein the second input/output port of the second DC/DC converter is connected across the load.
41. The converter of claim 40 , wherein the second DC/DC converter comprises a buck-boost converter.
42. The converter of claim 40 , wherein the second DC/DC converter comprises a flyback converter.
43. The converter of claim 40 , wherein the second DC/DC converter comprises an isolation transformer.
44. The converter of claim 43 , wherein the second input/output port comprises a center-tapped winding, a plurality of switches and a plurality of diodes or synchronous rectifiers, the switches and the diodes or synchronous rectifiers being organized in a full-bridge configuration.
45. The converter of claim 35 , wherein the first DC/DC converter further comprises a second output port and wherein the second output port of the first DC/DC converter and the second input/output port of the second DC/DC converter are connected in parallel.
46. The converter of claim 45 , wherein the second DC/DC converter comprises a buck-boost converter.
47. The converter of claim 46 , wherein the second input/output port comprises a plurality of switches organized in a full-bridge configuration.
48. The converter of claim 35 , wherein the input port of the first DC/DC converter and the second input/output port of the second DC/DC converter are connected in parallel.
49. The converter of claim 48 , wherein the second DC/DC converter comprises an isolating transformer.
50. The converter of claim 48 , wherein the second DC/DC converter comprises a buck-boost converter.
51. The converter of claim 48 , wherein the second DC/DC converter comprises a flyback converter.
52. The converter of claim 51 , wherein the second input/output port comprises a center-tapped winding, a plurality of switches and a plurality of diodes or synchronous rectifiers, the switches and the diodes or synchronous rectifiers being organized in a full-bridge configuration.