US5303138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low loss synchronous rectifier for application to clamped-mode power converters
Assignee: Nokia Bell Labs
•
Filing: 1993-04-29
•
Granted: 1994-04-12
•
Expires: 2013-04-29
Abstract
Abstract A synchronous rectifier for use with a clamped-mode power converter uses in one embodiment a hybrid rectifier with a MOSFET rectifying device active in one first cyclic interval of the conduction/nonconduction sequence of the power switch and a second rectifying device embodied in one illustrative embodiment as a low voltage bipolar diode rectifying device active during an alternative interval to the first conduction/nonconduction interval. The gate drive to the MOSFET device is continuous at a constant level for substantially all of the second interval which enhances efficiency of the rectifier. The bipolar rectifier device may also be embodied as a MOSFET device. The subject rectifier may be used in both forward and flyback power converters.
Inventors
- 👤 Allen F. Rozman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:20
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/02; H02M7/04; H02M7/12; H02M7/21; H02M7/217; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33569; H02M3/33576; H02M3/33592; Y; Y02; Y02B; Y02B70/00; Y02B70/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
129 words
In a power converter, comprising an input for accepting a DC voltage; a power transformer including a primary and secondary winding; a power switch for periodically connecting the input to the primary winding; an output for accepting a load to be energized; clamping means for limiting a voltage across the secondary winding during a specified interval of a cyclic period of the power converter; a rectifier circuit connecting the secondary winding to the output; and including: a synchronous rectification device connected for enabling conduction from the secondary winding to the output during operation of the clamping means during the specified interval; and a low forward voltage drop bipolar diode connected for enabling conduction from the secondary winding to the output during a second interval other than the specified interval.
Claim 2
Dependent Claim
129 words
In a power converter, comprising an input for accepting a DC voltage; a power transformer including a primary and secondary winding; a power switch for periodically connecting the input to the primary winding; an output for accepting a load to be energized; clamping means for limiting a voltage across the secondary winding during a specified interval of a cyclic period of the power converter; a rectifier circuit connecting the secondary winding to the output; and including: a synchronous rectification device connected for enabling conduction from the secondary winding to the output during operation of the clamping means during the specified interval; and a low forward voltage drop bipolar diode connected for enabling conduction from the secondary winding to the output during a second interval other than the specified interval.
Claim 3
Dependent Claim
128 words
In a power converter, comprising an input for accepting a DC voltage; a power transformer including a primary and secondary winding; a power switch for periodically connecting the input to the primary winding; an output for accepting a load to be energized; clamping means for limiting a voltage across the secondary winding during a specified interval of a cyclic period of the power converter; a rectifier circuit connecting the secondary winding to the output; and including: a first synchronous rectification device connected for enabling conduction from the secondary winding to the output during operation of the clamping means during the specified interval; and a second synchronous rectification device connected for enabling conduction from the secondary winding to the output during a second interval other than the specified interval.
Claim 4
Dependent Claim
128 words
In a power converter, comprising an input for accepting a DC voltage; a power transformer including a primary and secondary winding; a power switch for periodically connecting the input to the primary winding; an output for accepting a load to be energized; clamping means for limiting a voltage across the secondary winding during a specified interval of a cyclic period of the power converter; a rectifier circuit connecting the secondary winding to the output; and including: a first synchronous rectification device connected for enabling conduction from the secondary winding to the output during operation of the clamping means during the specified interval; and a second synchronous rectification device connected for enabling conduction from the secondary winding to the output during a second interval other than the specified interval.
Claim 5
Dependent Claim
23 words
In a power converter as claimed in claim 1 or 2, comprising the converter is connected to operate as a forward type converter.
Claim 6
Dependent Claim
23 words
In a power converter as claimed in claim 1 or 2, comprising the converter is connected to operate as a flyback type converter.
Claim 7
Dependent Claim
137 words
A switching mode power converter, comprising: a power transformer including a magnetizing inductance requiring periodic recycling; a first power stage for converting a DC input into a periodic pulsed voltage applied to a primary winding of the transformer; including: a clamping circuit for limiting a voltage of the transformer during the periodic recycling; a second power stage for rectifying an output of a secondary winding of the transformer and applying it to a load to be energized; including: a synchronous rectifier including a first rectifying device with a control gate responsive to a voltage of the secondary winding and biased periodically conducting and connected for conducting current from the secondary winding to the load; and a second rectifying device connected for conducting current from the secondary winding to the load when the first rectifying device is nonconducting.
Claim 8
Dependent Claim
137 words
A switching mode power converter, comprising: a power transformer including a magnetizing inductance requiring periodic recycling; a first power stage for converting a DC input into a periodic pulsed voltage applied to a primary winding of the transformer; including: a clamping circuit for limiting a voltage of the transformer during the periodic recycling; a second power stage for rectifying an output of a secondary winding of the transformer and applying it to a load to be energized; including: a synchronous rectifier including a first rectifying device with a control gate responsive to a voltage of the secondary winding and biased periodically conducting and connected for conducting current from the secondary winding to the load; and a second rectifying device connected for conducting current from the secondary winding to the load when the first rectifying device is nonconducting.
Claim 9
Dependent Claim
24 words
A switching mode power converter as claimed in claim 5, further comprising: the second rectifying device comprises a low forward voltage drop bipolar diode.
Claim 10
Dependent Claim
32 words
A switching mode power converter as claimed in claim 5, further comprising: the second rectifying device comprises a rectifying device with a control gate responsive to a voltage of the secondary winding.
Claim 11
Dependent Claim
51 words
A switching mode power converter as claimed in claim 6 or 7, further comprising: the secondary winding is tapped and separated into first and second winding segments; and the first rectifying device is connected to the first winding segment and the second rectifying device is connected to the second winding segment.
Claim 12
Dependent Claim
25 words
A switching mode power converter as claimed in claim 6 or 7, further comprising: the converter is connected to operate as a forward type converter.
Claim 13
Dependent Claim
25 words
A switching mode power converter as claimed in claim 6 or 7, further comprising: the converter is connected to operate as a flyback type converter.
References Cited (Backward Citations)
US4716514A
Cited
US4788634A
Cited
US4857822A
Cited
US4903189A
Cited
US4870555A
Cited
US5099406A
Cited
US5066900A
Cited
US5126931A
Cited
EP0508664A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-04-11 | 1997-10-11 | 1998-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-11 | 2001-10-11 | 2002-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-11 | 2005-10-11 | 2006-04-12 | $7700.00 | Window Closed / Lapsed |