US5115143A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Efficient P-channel FET drive circuit
Assignee: International Business Machines Corp
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Filing: 1991-08-08
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Granted: 1992-05-19
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Expires: 2011-08-08
Abstract
Abstract A drive circuit for a P-channel FET is provided which uses a switch means to bias the P-channel FET into conduction and passive components to bias the P-channel FET out of conduction, reducing the components required in the drive circuit and the power dissipated. Energy stored in an inductor while the P-channel FET is conducting is used to provide current through a capacitor in series with the gate to source capacitance of the P-channel FET reducing the stored charge and turning off the P-channel FET.
Inventors
- 👤 Alan S. Rohulich
- 👤 Ronnie A. Wunderlich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:55
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/687; H03K17/6871; H03K17/6872
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
A drive circuit for a P-channel field effect transistor comprising: a first and second input terminal couplable to a dc voltage source and a first and second output terminal, said second input and second output terminal coupled to one another, said P-channel field effect transistor having its source and drain terminals coupling the first input terminal to the first output terminal; a capacitor having one side coupled to the gate of the P-channel field effect transistor; switch means coupled between the other side of the capacitor and the second input terminal; and an inductor coupling said first input terminal and the junction of said switch means and said capacitor, said switch means when conductive and nonconductive causing said P-channel transistor to be biased into and out of conduction, respectively.
Claim 2
Dependent Claim
129 words
A drive circuit for a P-channel field effect transistor comprising: a first and second input terminal couplable to a dc voltage source and a first and second output terminal, said second input and second output terminal coupled to one another, said P-channel field effect transistor having its source and drain terminals coupling the first input terminal to the first output terminal; a capacitor having one side coupled to the gate of the P-channel field effect transistor; switch means coupled between the other side of the capacitor and the second input terminal; and an inductor coupling said first input terminal and the junction of said switch means and said capacitor, said switch means when conductive and nonconductive causing said P-channel transistor to be biased into and out of conduction, respectively.
Claim 3
Dependent Claim
13 words
The drive circuit of claim 1 wherein said switch means comprises a transistor.
Claim 4
Dependent Claim
22 words
The drive circuit of claim 1 further comprising voltage limiting means connected across the gate and source terminals of the P-channel transistor.
Claim 5
Dependent Claim
15 words
The drive circuit of claim 1 further comprising a resistor in series with said inductor.
Claim 6
Dependent Claim
15 words
The drive circuit of claim 1 further comprising a resistor in parallel with said capacitor.
Claim 7
Dependent Claim
17 words
The drive circuit of claim 3 wherein said voltage limiting means comprises back to back zener diodes.
Claim 8
Dependent Claim
15 words
The drive circuit of claim 2 wherein said switch comprises an N-channel field effect transistor.
References Cited (Backward Citations)
US4894568A
Cited
US4890021A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-19 | 1995-11-18 | 1996-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-19 | 1999-11-18 | 2000-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-19 | 2003-11-18 | 2004-05-19 | $7700.00 | Window Closed / Lapsed |