US5332938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High voltage MOSFET switching circuit
Assignee: United States Department of Energy
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Filing: 1992-04-06
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Granted: 1994-07-26
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Expires: 2012-04-06
Abstract
Abstract The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.
Inventors
- 👤 Thomas E. McEwan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:05
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/04; H03K17/041; H03K17/0412; H03K17/04123; H03K17/06; H03K17/063; H03K17/16; H03K17/161; H03K17/162
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
133 words
A MOSFET switching circuit comprising: a MOSFET transistor having a drain D connected to a high voltage source through a load, a source S connected to ground through a source circuit including source lead inductance L2, and a gate G connected to a current source, wherein the source lead inductance L2 produces a source lead inductive drop; a gate circuit connected from the gate G to ground, the gate circuit including a compensating inductor L1 having a value selected to produce an inductive spike in the gate circuit to compensate for the source lead inductive drop; wherein the source circuit further includes a series resistance R2 in series with source lead inductance L2 and the gate circuit further includes a series resistance R1 in series with compensating inductor L1 and L1 =(R1/R2) L2.
Claim 2
Dependent Claim
133 words
A MOSFET switching circuit comprising: a MOSFET transistor having a drain D connected to a high voltage source through a load, a source S connected to ground through a source circuit including source lead inductance L2, and a gate G connected to a current source, wherein the source lead inductance L2 produces a source lead inductive drop; a gate circuit connected from the gate G to ground, the gate circuit including a compensating inductor L1 having a value selected to produce an inductive spike in the gate circuit to compensate for the source lead inductive drop; wherein the source circuit further includes a series resistance R2 in series with source lead inductance L2 and the gate circuit further includes a series resistance R1 in series with compensating inductor L1 and L1 =(R1/R2) L2.
Claim 3
Dependent Claim
33 words
The circuit of claim 1 wherein the high voltage source is greater than 100 V and switching currents flowing through the MOSFET transistor from drain D to source S are greater than 1A.
Claim 4
Dependent Claim
138 words
In a MOSFET switching circuit comprising a MOSFET transistor having a drain D connected to a high voltage source through a load, a source S connected to ground through a source circuit including source lead inductance L2 which produces a source lead inductive drop, a gate G connected to a current source, and a gate circuit connected from the gate G to ground, a method of increasing switching speed comprising providing a compensating inductor L1 in the gate circuit having a value selected to produce an inductive spike in the gate circuit to compensate for the source lead inductive drop, wherein the source circuit further includes a series resistance R2 in series with source lead inductance L2 and the gate circuit further includes a series resistance R1 in series with compensating inductor L1, and further comprising selecting L1=(R1/R2)L2.
Claim 5
Dependent Claim
138 words
In a MOSFET switching circuit comprising a MOSFET transistor having a drain D connected to a high voltage source through a load, a source S connected to ground through a source circuit including source lead inductance L2 which produces a source lead inductive drop, a gate G connected to a current source, and a gate circuit connected from the gate G to ground, a method of increasing switching speed comprising providing a compensating inductor L1 in the gate circuit having a value selected to produce an inductive spike in the gate circuit to compensate for the source lead inductive drop, wherein the source circuit further includes a series resistance R2 in series with source lead inductance L2 and the gate circuit further includes a series resistance R1 in series with compensating inductor L1, and further comprising selecting L1=(R1/R2)L2.
Claim 6
Dependent Claim
31 words
The method of claim 3 for a high voltage source greater than 100 V and switching currents greater than 1A flowing through the MOSFET transistor from drain D to source S.
Claim 7
Dependent Claim
157 words
A MOSFET switching circuit comprising: a MOSFET transistor having a drain D connected to a high voltage source through a load, a source S connected to ground through a source circuit including source lead inductance L2, and a gate G connected to a current source, wherein the source lead inductance L2 produces a source lead inductive drop; a gate circuit connected from the gate G to ground, the gate circuit including a compensating inductor L1 having a value selected to produce an inductive spike in the gate circuit to compensate for the source lead inductive drop; wherein the source circuit further includes a series resistance R2 in series with source lead inductance L2 and the gate circuit further includes a series resistance R1 in series with compensating inductor L1; and wherein R1 is in the range 0-10Ω, R2 is in the range 0-1Ω, L2 in the range 0.1-10 nH, and L1 is in the range 1-100 nH.
Claim 8
Dependent Claim
157 words
A MOSFET switching circuit comprising: a MOSFET transistor having a drain D connected to a high voltage source through a load, a source S connected to ground through a source circuit including source lead inductance L2, and a gate G connected to a current source, wherein the source lead inductance L2 produces a source lead inductive drop; a gate circuit connected from the gate G to ground, the gate circuit including a compensating inductor L1 having a value selected to produce an inductive spike in the gate circuit to compensate for the source lead inductive drop; wherein the source circuit further includes a series resistance R2 in series with source lead inductance L2 and the gate circuit further includes a series resistance R1 in series with compensating inductor L1; and wherein R1 is in the range 0-10Ω, R2 is in the range 0-1Ω, L2 in the range 0.1-10 nH, and L1 is in the range 1-100 nH.
Claim 9
Dependent Claim
12 words
The circuit of claim 5 wherein R1=1Ω, R2=0.1Ω, L1=40 nH, L2=4 nH.
Claim 10
Dependent Claim
22 words
The method of claim 3 wherein the MOSFET transistor with compensating inductor has a switching time on the order of 2 ns.
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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) | 1997-07-25 | 1998-01-24 | 1998-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-25 | 2002-01-24 | 2002-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-25 | 2006-01-24 | 2006-07-26 | $7700.00 | Window Closed / Lapsed |