US4952827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for controlling the load current in a power MOSFET
Assignee: Siemens AG
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Filing: 1989-11-15
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Granted: 1990-08-28
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Expires: 2009-11-15
Abstract
Abstract A circuit arrangement for controlling load current of a power MOSFET wherein the load is connected at the source terminal includes a second FET having a defined threshold voltage connected with its drain-source path inserted between the gate and source of the power MOSFET. A third FET connects the gate terminal of the second FET to the drain voltage of the power MOSFET when the power MOSFET is in the conductive condition. When the drain-source voltage of the power MOSFET becomes higher than the threshold voltage of the second FET, the second FET becomes conductive and drives the gate-source voltage of the power MOSFET down.
Inventors
- 👤 Ludwig Leipold
- 👤 Rainald Sander
- 👤 Jenoe Tihanyi
- 👤 Roland Weber
- 👤 Nance: Paul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:10
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/08; H03K17/082; H03K17/0822; H03K17/06; H03K17/063
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
143 words
A circuit arrangement for controlling a load current from a power MOSFET to a load connected in series with a source terminal of the power MOSFET, comprising: a second MOSFET having a drain-source path connected between a gate terminal and a source terminal of the power MOSFET, said second MOSFET having a threshold voltage that is higher than a drain-source voltage drop of the power MOSFET at nominal current; a third MOSFET having a source terminal connected to a gate terminal of said second MOSFET and having a drain terminal connected to a drain terminal of the power MOSFET, said third MOSFET having a gate terminal connected to the gate terminal of the power MOSFET; and a current source having first terminal connected to a gate terminal of said second MOSFET, said current source having a second terminal connected to a fixed potential.
Claim 2
Dependent Claim
143 words
A circuit arrangement for controlling a load current from a power MOSFET to a load connected in series with a source terminal of the power MOSFET, comprising: a second MOSFET having a drain-source path connected between a gate terminal and a source terminal of the power MOSFET, said second MOSFET having a threshold voltage that is higher than a drain-source voltage drop of the power MOSFET at nominal current; a third MOSFET having a source terminal connected to a gate terminal of said second MOSFET and having a drain terminal connected to a drain terminal of the power MOSFET, said third MOSFET having a gate terminal connected to the gate terminal of the power MOSFET; and a current source having first terminal connected to a gate terminal of said second MOSFET, said current source having a second terminal connected to a fixed potential.
Claim 3
Dependent Claim
61 words
A circuit arrangement as claimed in claim 1, wherein said second and third MOSFETs have threshold voltages selected such that a sum of the threshold voltages of the second and third MOSFETs enable the power MOSFET to operate at a point at an upper end of a linear region of a drain current/drain-source voltage characteristic field at a prescribed nominal current.
Claim 4
Dependent Claim
151 words
A circuit arrangement for connection to a power MOSFET to control load current from a source terminal of the power MOSFET to control load current from a source terminal of the power MOSFET to a load, comprising: a second FET having a threshold voltage and being connected with its drain-source path between a gate and a source of the power MOSFET; a third FET having a threshold voltage and having its gate connected to a gate of the power MOSFET, a drain-source path of said third FET being connected between a drain of the power MOSFET and a gate of said second FET; a current source connected between said gate of said second FET and ground; and said threshold voltages of said second and third FETs being such that a sum thereof places a nominal current of the power MOSFET at an upper region of a drain current/drain-source voltage characteristic field.
Claim 5
Dependent Claim
151 words
A circuit arrangement for connection to a power MOSFET to control load current from a source terminal of the power MOSFET to control load current from a source terminal of the power MOSFET to a load, comprising: a second FET having a threshold voltage and being connected with its drain-source path between a gate and a source of the power MOSFET; a third FET having a threshold voltage and having its gate connected to a gate of the power MOSFET, a drain-source path of said third FET being connected between a drain of the power MOSFET and a gate of said second FET; a current source connected between said gate of said second FET and ground; and said threshold voltages of said second and third FETs being such that a sum thereof places a nominal current of the power MOSFET at an upper region of a drain current/drain-source voltage characteristic field.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |