US4603268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Totem pole output circuit with reduced current spikes
Assignee: National Semiconductor Corp
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Filing: 1983-12-14
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Granted: 1986-07-29
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Expires: 2003-12-14
Abstract
Abstract A totem pole output stage is shown where current spikes are minimized. The circuit disclosed employs four transistors and three diodes to eliminate the spikes associated with the input low to high transition. A fourth diode minimizes the input high to low transition time.
Inventors
- 👤 Walter R. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:15
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/30; H03F3/3083; H03F3/3084
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
234 words
A totem pole transistor output stage circuit capable of sourcing and sinking output current in a load, said circuit having signal input and output terminals and comprising: first and second power supply terminals connectable to a source of operating power; a first output transistor having its emitter coupled to said output terminal, its collector coupled to said first power supply terminal, and a base; a first driver transistor coupled in Darlington configuration to drive said first output transistor and having a base; a second output transistor having its collector coupled to said output terminal, its emitter coupled to said second power supply terminal, and a base coupled to said input terminal; a first diode coupled in series between said collector of said second output transistor and said output terminal and poled in a same direction as the base-emitter junction of the second output transistor; a second diode coupled between said collector of said second output transistor and said base of said first output transistor and poled in a same direction as the base-emitter junction of the second output transistor; a third diode coupled between said collector of said second output transistor and said base of said first driver transistor and poled in a same direction as the base-emitter junction of the second output transistor; and a constant current device coupled between said first power supply terminal and said base of said first driver transistor.
Claim 2
Dependent Claim
234 words
A totem pole transistor output stage circuit capable of sourcing and sinking output current in a load, said circuit having signal input and output terminals and comprising: first and second power supply terminals connectable to a source of operating power; a first output transistor having its emitter coupled to said output terminal, its collector coupled to said first power supply terminal, and a base; a first driver transistor coupled in Darlington configuration to drive said first output transistor and having a base; a second output transistor having its collector coupled to said output terminal, its emitter coupled to said second power supply terminal, and a base coupled to said input terminal; a first diode coupled in series between said collector of said second output transistor and said output terminal and poled in a same direction as the base-emitter junction of the second output transistor; a second diode coupled between said collector of said second output transistor and said base of said first output transistor and poled in a same direction as the base-emitter junction of the second output transistor; a third diode coupled between said collector of said second output transistor and said base of said first driver transistor and poled in a same direction as the base-emitter junction of the second output transistor; and a constant current device coupled between said first power supply terminal and said base of said first driver transistor.
Claim 3
Dependent Claim
29 words
The circuit of claim 1 wherein said base of said second output transistor is driven from an emitter follower transistor having its base coupled to said signal input terminal.
Claim 4
Dependent Claim
39 words
The circuit of claim 2 further including a fourth diode coupled between said collector of said second output transistor and said base of said emitter follower transistor and poled to be conductive when said second output transistor is conductive.
References Cited (Backward Citations)
US4228371A
Cited
US4467226A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-28 | 1990-01-27 | 1990-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-28 | 1994-01-27 | 1994-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-28 | 1998-01-27 | 1998-07-29 | $7700.00 | Window Closed / Lapsed |