US5677619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for multiple output regulation in a step-down switching regulator
Assignee: Maxim Integrated Products Inc
•
Filing: 1996-07-01
•
Granted: 1997-10-14
•
Expires: 2016-07-01
Abstract
Abstract A step-down switching regulator of the present invention includes (1) a magnetic storage device having at least one primary output and one secondary output, (2) a current sensing device for detecting current through a primary winding of the magnetic storage device, (3) a first switch, (4) a second switch, (5) a first comparator for detecting whether the current through the primary winding is greater than a limit value, (6) a second comparator for detecting loss of regulation in the secondary output, and (7) a switch logic circuitry for allowing only one of the first switch or the second switch to turn on at a time. When the primary output is out of regulation, the first switch turns on to deliver power to the primary output. When the secondary output is out of regulation, one of two methods can be used to supply power to the secondary output. A first method turns on the first switch for a short time, and then the second switch turns on to deliver power to the secondary output. A second method turns on the second switch without first turning on the first switch. In either methods, the second switch can be turned off at the end of a pre-determined time period, at the end of a clock cycle, when the current through the primary winding exceeds a pre-determined limit value, or when the current through the primary winding is substantially zero.
Inventors
- 👤 Tunc Doluca
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:40
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33561; G; G05; G05F; G05F1/00; G05F1/10; G05F1/12; G05F1/32; H02M1/00; H02M1/0083; H02M1/009
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
139 words
A method of operating a switching regulator having a transformer with a primary and at least one secondary winding and having a first regulator output coupled to one end of the primary winding and a second regulator output coupled to the secondary winding, a second end of the primary winding being coupled to first and second switches for controllably coupling the second end of the primary winding to a first supply voltage and to a second supply voltage, respectively, comprising the steps of: (a) controlling the first and second switches to provide an average current through the primary of the transformer to maintain the first regulator output in regulation; and, (b) controlling the first and second switches to provide time rates of change of current through the primary of the transformer to maintain the second regulator output in regulation.
Claim 2
Independent Claim
139 words
A method of operating a switching regulator having a transformer with a primary and at least one secondary winding and having a first regulator output coupled to one end of the primary winding and a second regulator output coupled to the secondary winding, a second end of the primary winding being coupled to first and second switches for controllably coupling the second end of the primary winding to a first supply voltage and to a second supply voltage, respectively, comprising the steps of: (a) controlling the first and second switches to provide an average current through the primary of the transformer to maintain the first regulator output in regulation; and, (b) controlling the first and second switches to provide time rates of change of current through the primary of the transformer to maintain the second regulator output in regulation.
Claim 3
Dependent Claim
59 words
The method of claim 1 wherein when the second regulator output begins to loose regulation, step (b) comprises the step of turning on the first switch followed by the turning off of the first switch and turning on the second switch followed by turning off the second switch, successively as required to maintain regulation of the second regulator output.
Claim 4
Dependent Claim
114 words
The method of claim 1 wherein when the first regulator output begins to loose regulation, step (a) comprises the step of turning on the first switch followed by the turning off of the first switch and turning on the second switch followed by turning off the second switch, successively as required to maintain regulation of the second regulator output; and wherein when the second regulator output begins to loose regulation, step (b) comprises the step of turning on the first switch followed by the turning off of the first switch and turning on the second switch followed by turning off the second switch, successively as required to maintain regulation of the second regulator output.
Claim 5
Dependent Claim
44 words
The method of claim 1 wherein when the second regulator output begins to loose regulation, step (b) comprises the step of turning on the second switch followed by turning off the second switch, successively as required to maintain regulation of the second regulator output.
Claim 6
Dependent Claim
99 words
The method of claim 1 wherein when the first regulator output begins to loose regulation, step (a) comprises the step of turning on the first switch followed by the turning off of the first switch and turning on the second switch followed by turning off the second switch, successively as required to maintain regulation of the second regulator output; and wherein when the second regulator output begins to loose regulation, step (b) comprises the step of turning on the second switch followed by turning off the second switch, successively as required to maintain regulation of the second regulator output.
Claim 7
Dependent Claim
134 words
A step-down switching regulator comprising: a transformer with a primary and at least one secondary winding and having a first regulator output coupled to a first end of the primary winding having first and second ends, and a second regulator output coupled to the secondary winding; the second end of the primary winding being coupled to first and second switches for controllably coupling the second end of the primary winding to a first supply voltage and to a second supply voltage, respectively; and, a controller controlling the switches to provide currents through the primary of the transformer to maintain the first regulator output above a first predetermined voltage, and to provide time rates of change of currents through the primary of the transformer to maintain the second regulator output above a second predetermined voltage.
Claim 8
Dependent Claim
134 words
A step-down switching regulator comprising: a transformer with a primary and at least one secondary winding and having a first regulator output coupled to a first end of the primary winding having first and second ends, and a second regulator output coupled to the secondary winding; the second end of the primary winding being coupled to first and second switches for controllably coupling the second end of the primary winding to a first supply voltage and to a second supply voltage, respectively; and, a controller controlling the switches to provide currents through the primary of the transformer to maintain the first regulator output above a first predetermined voltage, and to provide time rates of change of currents through the primary of the transformer to maintain the second regulator output above a second predetermined voltage.
Claim 9
Dependent Claim
53 words
The step-down switching regulator of claim 6 wherein when the second regulator output begins to loose regulation, the controller turns on the first switch, then turns off the first switch and turns on the second switch, then turns off the second switch, successively as required to maintain regulation of the second regulator output.
Claim 10
Dependent Claim
100 words
The step-down switching regulator of claim 6 wherein when the first regulator output begins to loose regulation, the controller turns on the first switch, then turns off the first switch and turns on the second switch, then turns off the second switch, successively as required to maintain regulation of the second regulator output; and wherein when the second regulator output begins to loose regulation, the controller turns on the first switch, then turns off the first switch and turn on the second switch, then turns off the second switch, successively as required to maintain regulation of the second regulator output.
Claim 11
Dependent Claim
41 words
The step-down switching regulator of claim 6 wherein when the second regulator output begins to loose regulation, the controller turns on the second switch, then turns off the second switch, successively as required to maintain regulation of the second regulator output.
Claim 12
Dependent Claim
88 words
The step-down switching regulator of claim 6 wherein when the first regulator output begins to loose regulation, the controller turns on the first switch, then turns off the first switch and turns on the second switch, then turns off the second switch, successively as required to maintain regulation of the second regulator output; and wherein when the second regulator output begins to loose regulation, the controller turns on the second switch, then turns off the second switch, successively as required to maintain regulation of the second regulator output.
References Cited (Backward Citations)
US4454558A
Cited
US4881023A
Cited
US5019770A
Cited
US5257170A
Cited
US5070294A
Cited
US5386359A
Cited
US5418704A
Cited
US5397976A
Cited
US5422562A
Cited
US5532577A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-13 | 2001-04-14 | 2001-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-13 | 2005-04-14 | 2005-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-13 | 2009-04-14 | 2009-10-14 | $7700.00 | Window Closed / Lapsed |