US4868424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
TTL circuit with increased transient drive
Assignee: Semiconductor Components Industries LLC
•
Filing: 1987-11-24
•
Granted: 1989-09-19
•
Expires: 2007-11-24
Abstract
Abstract A circuit (C1, Q6) which provides additional drive current during substantially the entire transition of an output signal from a logical one to a logical zero state, thereby causing the pulldown transistor (Q4) in the TTL output stage to rapidly turn on, providing increased switching speed between logical one and logical zero output state for a given power consumption. Alternatively, for a given switching speed, power consumption is reduced.
Inventors
- 👤 Robert J. Bosnyak
- 👤 Jeff Huard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:59
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/0008; H03K19/001; H03K19/01; H03K19/013; H03K19/0136
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
142 words
A circuit comprising: an input terminal for receiving an input signal; an output terminal for providing an output signal in response to said input signal; first means connected to said output terminal for providing a first voltage to said output terminal in response too a first state of said input signal; second means connected to said output terminal for providing a second voltage to said output terminal in response to a second state of said input signal; control means responsive to said input signal for controlling the operation of said first means and said second means; and transient drive means for providing additional drive to said control means during substantially the entire transition of said output signal in response to a transition of said input signal without regard to changes in the level of said input and output signals during said transition.
Claim 2
Dependent Claim
142 words
A circuit comprising: an input terminal for receiving an input signal; an output terminal for providing an output signal in response to said input signal; first means connected to said output terminal for providing a first voltage to said output terminal in response too a first state of said input signal; second means connected to said output terminal for providing a second voltage to said output terminal in response to a second state of said input signal; control means responsive to said input signal for controlling the operation of said first means and said second means; and transient drive means for providing additional drive to said control means during substantially the entire transition of said output signal in response to a transition of said input signal without regard to changes in the level of said input and output signals during said transition.
Claim 3
Dependent Claim
44 words
A circuit as in claim 1 wherein said transient drive means provides additional drive to said control means in response to a voltage change on said control means without regard to changes in the level of said input and output signals during said transition.
Claim 4
Dependent Claim
40 words
A circuit as in claim 2 further comprising means for providing said additional drive to said control means for a predetermined period of time without regard to changes in the levels of said input and output signals during said transition.
Claim 5
Dependent Claim
23 words
A circuit as in claim 1 wherein said predetermined period of time is selected based on the fall time of said output signal.
Claim 6
Dependent Claim
31 words
A circuit as in claim 1 wherein said transient drive means comprises a capacitance for storing charge and a transistor for Beta multiplying said stored charge to provide said additional drive.
Claim 7
Dependent Claim
16 words
A circuit as in claim 5 wherein said capacitance comprises stray capacitance in a semiconductor device.
Claim 8
Dependent Claim
47 words
A circuit as in claim 5 wherein said transient drive means further comprises means to charge said capacitance when said output signal is in a first state and means for discharging said capacitance when said output signal is transitioning from said first state to a second state.
Claim 9
Dependent Claim
29 words
A circuit as in claim 7 wherein said capacitance has been substantially charged when said output signal has completed said transition from said first state to said second state.
Claim 10
Dependent Claim
25 words
A circuit as in claim 1, wherein said transient drive means further comprises current setting means for determining the maximum value of said additional drive.
Claim 11
Dependent Claim
14 words
A circuit as in claim 9 wherein said current setting means comprises a resistor.
Claim 12
Dependent Claim
22 words
A circuit as in claim 1 wherein said transient drive means further comprises means for setting the duration of said additional drive.
Claim 13
Dependent Claim
14 words
A circuit as in claim 11 wherein said means for setting comprises a resistor.
Claim 14
Dependent Claim
100 words
A circuit as in claim 1 wherein said transient drive means comprises: a transistor having a first current handling terminal coupled to a supply voltage, a second current handling terminal coupled to said control means, and a control terminal; a capacitance coupled to said control terminal; and means for charging said capacitance to a selected value when said output signal is in a first state; wherein the charge on said capacitance turns said transistor on when said output signal transitions from said first state to a second state, thereby causing said transistor to provide additional drive to said control means.
Claim 15
Dependent Claim
39 words
A circuit as in claim 13 wherein said means for charging comprises a diode having a first lead connected to said control terminal of said transistor and a second lead connected to said second current handling of said transistor.
Claim 16
Dependent Claim
13 words
A circuit as in claim 14 wherein said diode is a Schottky diode.
Claim 17
Dependent Claim
41 words
A circuit as in claim 14 wherein said diode comprises a transistor having its base coupled to its collector, and its base serves as a first lead to said diode, and its emitter serves as a second lead of said diode.
Claim 18
Dependent Claim
41 words
A circuit as in claim 14 wherein said diode comprises a transistor having a collector serving as a first lead of said diode, an emitter serving as a second lead of said diode, and a base coupled to a bias voltage.
Claim 19
Dependent Claim
20 words
A circuit as in claim 13 wherein said capacitance comprises stray capacitance connected to said control terminal of said transistor.
Claim 20
Dependent Claim
25 words
A circuit as in claim 13 wherein said transient drive means further comprises current setting means for determining the maximum value of said additional drive.
Claim 21
Dependent Claim
25 words
A circuit as in claim 19 wherein said current setting means comprises a resistor connected between said supply voltage and said first current handling terminal.
Claim 22
Dependent Claim
22 words
A circuit as in claim 13 wherein said transient drive means further comprises means for setting the duration of said additional drive.
Claim 23
Dependent Claim
22 words
A circuit as in claim 21 wherein said means for setting comprises a resistor coupled in parallel with said means for charging.
Claim 24
Independent Claim
59 words
A method for controlling the transition of an output signal from a first state to a second state comprising the step of providing a transient drive current during substantially the entire transition of said output signal from said first state said second state without regard to changes in the level of said input and output signals during said transition.
Claim 25
Independent Claim
59 words
A method for controlling the transition of an output signal from a first state to a second state comprising the step of providing a transient drive current during substantially the entire transition of said output signal from said first state said second state without regard to changes in the level of said input and output signals during said transition.
Claim 26
Dependent Claim
23 words
A method as in claim 23 wherein said transient drive current is provided by a transient drive circuit having means for storing charge.
Claim 27
Dependent Claim
17 words
A method as in claim 24 wherein said charge is discharged to control said transient drive current.
Claim 28
Dependent Claim
30 words
A method as in claim 25 wherein said means for storing charge is substantially charged during the transition of said output signal from said second state to said first state.
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) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |