US4841166A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Limiting shoot-through current in a power MOSFET half-bridge during intrinsic diode recovery
Assignee: Vishay Siliconix Inc
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Filing: 1987-07-17
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Granted: 1989-06-20
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Expires: 2007-07-17
Abstract
Abstract A novel closed loop feedback circuit is provided which senses the shoot-through current of a power switching device driving an inductive load. If excessive shoot-through current is sensed, the closed loop causes a reduction of the gate drive to the Power MOSFET contained in the power switching circuit, thereby slowing its turn on time, and in turn reducing the shoot-through current.
Inventors
- 👤 James A. Harnden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:30
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/08; H03K17/082; H03K17/0822; H03K17/51; H03K17/56; H03K17/687; H03K17/6871; H03K17/6877
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
185 words
A circuit for switching current to an inductive load comprising: a high-side MOSFET with an intrinsic body-drain diode to clamp inductive flyback energy, said high-side MOSFET having a drain connected to a supply voltage, a source, and a gate connected to a source of bias potential; a low-side N-channel MOSFET having a source connected to a supply return, a drain connected to said source of said high-side MOSFET and through an inductive load to said supply return, and a gate; means for sensing the current between said source and drain of said low-side MOSFET; a control input terminal for receiving a control signal indicating when said low-side MOSFET is to turn on; and means responsive to said control signal for supplying a bias signal to said gate of said low-side MOSFET in order to cause said low-side MOSFET to turn on, said means responsive reducing said bias signal when said means for sensing determines that said current flow between said source and drain of said low-side MOSFET exceeds a predetermined magnitude during the recovery time (Trr) of said intrinsic body-drain diode of said high-side MOSFET.
Claim 2
Dependent Claim
185 words
A circuit for switching current to an inductive load comprising: a high-side MOSFET with an intrinsic body-drain diode to clamp inductive flyback energy, said high-side MOSFET having a drain connected to a supply voltage, a source, and a gate connected to a source of bias potential; a low-side N-channel MOSFET having a source connected to a supply return, a drain connected to said source of said high-side MOSFET and through an inductive load to said supply return, and a gate; means for sensing the current between said source and drain of said low-side MOSFET; a control input terminal for receiving a control signal indicating when said low-side MOSFET is to turn on; and means responsive to said control signal for supplying a bias signal to said gate of said low-side MOSFET in order to cause said low-side MOSFET to turn on, said means responsive reducing said bias signal when said means for sensing determines that said current flow between said source and drain of said low-side MOSFET exceeds a predetermined magnitude during the recovery time (Trr) of said intrinsic body-drain diode of said high-side MOSFET.
Claim 3
Dependent Claim
33 words
A circuit as in claim 1 wherein said bias signal is further reduced in response to further increases in current between said source and drain of said low-side MOSFET above said predetermined magnitude.
Claim 4
Dependent Claim
26 words
A circuit as in claim 1 wherein said means for sensing comprises a resistor connected in the path between said supply voltage and said supply return.
Claim 5
Dependent Claim
25 words
A circuit as in claim 1 wherein said reduction of said bias signal serves to limit said current flow between said source and drain terminals.
Claim 6
Dependent Claim
16 words
A circuit as in claim 4 wherein said current is limited to approximately said predetermined magnitude.
Claim 7
Dependent Claim
13 words
A circuit as in claim 1 wherein said means responsive comprises a transistor.
Claim 8
Dependent Claim
185 words
A circuit for switching current to an inductive load comprising: a low-side MOSFET with an intrinsic body-drain diode to clamp inductive flyback energy, said low-side MOSFET having a drain connected to a supply return, a source, and a gate connected to a source of bias potential; a high-side P-channel MOSFET having a source connected to a supply voltage, a drain connected to said source of said low-side MOSFET and through an inductive load to said supply return, and a gate; means for sensing the current between said source and drain of said high-side MOSFET; a control input terminal for receiving a control signal indicating when said high-side MOSFET is to turn on; and means responsive to said control signal for supplying a bias signal to said gate of said high-side MOSFET in order to cause said high-side MOSFET to turn on, said means responsive reducing said bias signal when said means for sensing determines that said current flow between said source and drain of said high-side MOSFET exceeds a predetermined magnitude during the recovery time (Trr) of said intrinsic body-drain diode of said low-side MOSFET.
Claim 9
Dependent Claim
185 words
A circuit for switching current to an inductive load comprising: a low-side MOSFET with an intrinsic body-drain diode to clamp inductive flyback energy, said low-side MOSFET having a drain connected to a supply return, a source, and a gate connected to a source of bias potential; a high-side P-channel MOSFET having a source connected to a supply voltage, a drain connected to said source of said low-side MOSFET and through an inductive load to said supply return, and a gate; means for sensing the current between said source and drain of said high-side MOSFET; a control input terminal for receiving a control signal indicating when said high-side MOSFET is to turn on; and means responsive to said control signal for supplying a bias signal to said gate of said high-side MOSFET in order to cause said high-side MOSFET to turn on, said means responsive reducing said bias signal when said means for sensing determines that said current flow between said source and drain of said high-side MOSFET exceeds a predetermined magnitude during the recovery time (Trr) of said intrinsic body-drain diode of said low-side MOSFET.
Claim 10
Dependent Claim
33 words
A circuit as in claim 7 wherein said bias signal is further reduced in response to further increases in current between said source and drain of said high-side MOSFET above said predetermined magnitude.
Claim 11
Dependent Claim
26 words
A circuit as in claim 7 wherein said means for sensing comprises a resistor connected in the path between said supply voltage and said supply return.
Claim 12
Dependent Claim
25 words
A circuit as in claim 7 wherein said reduction of said bias signal serves to limit said current flow between said source and drain terminals.
Claim 13
Dependent Claim
16 words
A circuit as in claim 10 wherein said current is limited to approximately said predetermined magnitude.
Claim 14
Dependent Claim
13 words
A circuit as in claim 7 wherein said means responsive comprises a transistor.
Claim 15
Dependent Claim
22 words
A circuit as in claim 3 wherein said resistor is connected between said supply return and said source of said low-side MOSFET.
Claim 16
Dependent Claim
22 words
A circuit as in claim 9 wherein said resistor is connected between said voltage supply and said source of said high-side MOSFET.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |