Patent US4528463A successfully refreshed from Google Patents.
US4528463A
Expired / Lapsed
US
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Bipolar digital peripheral driver transistor circuit
Assignee: National Semiconductor Corp
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Filing: 1982-06-30
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Granted: 1985-07-09
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Expires: 2002-06-30
Abstract
Abstract A digital driver circuit employs an output transistor having an uncommitted collector that can act as a current sink connectable to a peripheral element that is to be controlled. The base of the output transistor is coupled to a driver circuit that controls the output transistor conduction. The driver input is coupled to a pair of cascaded current mirrors which act to switch the driver off and on. An input stage is coupled to control the current mirrors in response to a low current logic signal.
Inventors
- 👤 David Kung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:19
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/60; H03K19/00; H03K19/0175; H03K19/018; H03K19/01806; H03K5/00; H03K5/01; H03K5/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
An integrated digital peripheral driver circuit comprising: an output stage capable of sinking relatively large values of current; driver means having an input responsive to an input signal for turning said output stage on and off; input means for supplying a signal for turning said driver means on and off comprising: first current mirror means having an input and an output coupled to said input of said driver means; second current mirror means having an input and an output coupled to said input of said first current mirror; and an input stage connected as an emitter follower coupled to drive said input of said second current mirror.
Claim 2
Dependent Claim
107 words
An integrated digital peripheral driver circuit comprising: an output stage capable of sinking relatively large values of current; driver means having an input responsive to an input signal for turning said output stage on and off; input means for supplying a signal for turning said driver means on and off comprising: first current mirror means having an input and an output coupled to said input of said driver means; second current mirror means having an input and an output coupled to said input of said first current mirror; and an input stage connected as an emitter follower coupled to drive said input of said second current mirror.
Claim 3
Dependent Claim
31 words
The circuit of claim 1 wherein said first and second current mirrors are ratioed with respect to said driver means to control the on and off states of said output means.
Claim 4
Dependent Claim
64 words
The circuit of claim 2 wherein said first current mirror comprises: an input current source connected to pass a constant current through a first diode means; means for coupling said first diode means to said input of said driver means; and means for adjusting the current transfer in said first current mirror whereby said mirrored current is insufficient to saturate said driver means input.
Claim 5
Dependent Claim
58 words
The circuit of claim 3 wherein said second current mirror is coupled to said first current mirror, is driven by said input stage, and includes means for ratioing whereby when said input stage is rendered conductive by an input thereto, the current delivered by said first current mirror is sufficient to saturate the input of said driver means.
References Cited (Backward Citations)
US4166964A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-08 | 1989-01-07 | 1989-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-08 | 1993-01-07 | 1993-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-08 | 1997-01-07 | 1997-07-09 | $7700.00 | Window Closed / Lapsed |