Patent US4725912A successfully refreshed from Google Patents.
US4725912A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power MOS loss of ground protection
Assignee: Semiconductor Components Industries LLC
•
Filing: 1987-07-27
•
Granted: 1988-02-16
•
Expires: 2007-07-27
Abstract
Abstract A power MOS switching device is provided wherein certain protective circuits in a control portion thereof remain functional when a ground connection to said control portion is lost.
Inventors
- 👤 Robert S. Wrathall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:26
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/08; H03K17/082; H03K17/0822; H03K17/081; H03K17/0812; H03K17/08122
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
145 words
A power switching device comprising a power transistor having a control terminal and first and second load current terminals; a control circuit having input, drive and first and second voltage supply terminals, said first load current terminal coupled to said first voltage supply terminal for connection to a first voltage reference, said drive terminal coupled to said control terminal, said second voltage supply terminal coupled to a second voltage reference, and said second load current terminal for coupling to a third voltage reference; and a diode having anode and cathode terminals, said anode terminal coupled at said second voltage supply terminal and said cathode terminal coupled at said second load current terminal for providing a current path from said second voltage supply terminal to said second load current terminal when said connection from said second voltage supply terminal to said second voltage reference is lost.
Claim 2
Dependent Claim
145 words
A power switching device comprising a power transistor having a control terminal and first and second load current terminals; a control circuit having input, drive and first and second voltage supply terminals, said first load current terminal coupled to said first voltage supply terminal for connection to a first voltage reference, said drive terminal coupled to said control terminal, said second voltage supply terminal coupled to a second voltage reference, and said second load current terminal for coupling to a third voltage reference; and a diode having anode and cathode terminals, said anode terminal coupled at said second voltage supply terminal and said cathode terminal coupled at said second load current terminal for providing a current path from said second voltage supply terminal to said second load current terminal when said connection from said second voltage supply terminal to said second voltage reference is lost.
Claim 3
Dependent Claim
13 words
The circuit of claim 1 wherein said power transistor is a MOS transistor.
Claim 4
Dependent Claim
14 words
The circuit of claim 1 wherein said control circuit is a CMOS control circuit.
Claim 5
Dependent Claim
15 words
The circuit of claim 1 wherein said power switching device is a single integrated circuit.
Claim 6
Dependent Claim
20 words
The circuit of claim 1 where said second voltage reference and said third voltage reference are substantially the same value.
Claim 7
Dependent Claim
18 words
The circuit of claim 5 wherein said second voltage reference and said third voltage reference are physically separated.
References Cited (Backward Citations)
US3996497A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-15 | 1991-08-17 | 1992-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-15 | 1995-08-17 | 1996-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-15 | 1999-08-17 | 2000-02-16 | $7700.00 | Window Closed / Lapsed |