US3873856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit having a voltage hysteresis for use as a schmitt trigger
Assignee: TDK Micronas GmbH
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Filing: 1973-10-17
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Granted: 1975-03-25
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Expires: 1993-10-17
Abstract
Abstract This invention relates to a Schmitt-trigger circuit realized by MOS techniques employing insulated-gate field-effect transistors. To the common MOS inverter there is added a switched current source feeding a current to a series resistor thereby generating a voltage drop which is added to the inverter threshold voltage. The current source is switched on if the inverter transistor is blocked by the input signal.
Inventors
- 👤 Albrecht Gerlach
- 👤 Gunter Lindstedt
- 👤 Wolfgang Gollinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:12
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/353; H03K3/356; H03K3/3565
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
293 words
A monolithic integrated circuit having a voltage hysteresis for use as a Schmitt trigger comprising: a source of supply voltage; an insulated-gate field-effect driver transistor having source, gate and drain electrodes, said gate electrode for receiving an input singal; a first insulated-gate field-effect transistor having source, gate and drain electrodes, said drain electrode coupled to said source of supply voltage, said gate electrode coupled to the gate electrode of said driver transistor, and the source electrode coupled to the drain electrode of said driver transistor; a second insulated-gate field-effect transistor having source, drain and gate electrodes, said drain electrode coupled to said source of supply voltage and said source electrode coupled to the source electrode of said driver transistor for supplying additional current to the source of said driver transistor; a third insulated-gate field-effect transistor having source, drain and gate electrodes, said gate electrode coupled to said source of supply voltage, said source electrode coupled to the zero point of the circuit, and said drain electrode coupled to the source electrode of said driver transistor and source electrode of said second transistor; a fourth insulated-gate field-effect transistor having source, drain and gate electrodes, said drain electrode coupled to said source of supply voltage and said source electrode coupled to the gate electrode of said second transistor; and a fifth insulated-gate field-effect transistor having source, drain and gate electrodes, said source electrode coupled to the zero point of the circuit, said drain electrode coupled to the source electrode of said fourth transistor and the gate electrode of said second transistor, and said gate electrode coupled to the gate electrode of said fourth transistor and the drain electrode of said driver transistor, said fourth and fifth transistor forming an inverter for controlling said second transistor.
Claim 2
Dependent Claim
293 words
A monolithic integrated circuit having a voltage hysteresis for use as a Schmitt trigger comprising: a source of supply voltage; an insulated-gate field-effect driver transistor having source, gate and drain electrodes, said gate electrode for receiving an input singal; a first insulated-gate field-effect transistor having source, gate and drain electrodes, said drain electrode coupled to said source of supply voltage, said gate electrode coupled to the gate electrode of said driver transistor, and the source electrode coupled to the drain electrode of said driver transistor; a second insulated-gate field-effect transistor having source, drain and gate electrodes, said drain electrode coupled to said source of supply voltage and said source electrode coupled to the source electrode of said driver transistor for supplying additional current to the source of said driver transistor; a third insulated-gate field-effect transistor having source, drain and gate electrodes, said gate electrode coupled to said source of supply voltage, said source electrode coupled to the zero point of the circuit, and said drain electrode coupled to the source electrode of said driver transistor and source electrode of said second transistor; a fourth insulated-gate field-effect transistor having source, drain and gate electrodes, said drain electrode coupled to said source of supply voltage and said source electrode coupled to the gate electrode of said second transistor; and a fifth insulated-gate field-effect transistor having source, drain and gate electrodes, said source electrode coupled to the zero point of the circuit, said drain electrode coupled to the source electrode of said fourth transistor and the gate electrode of said second transistor, and said gate electrode coupled to the gate electrode of said fourth transistor and the drain electrode of said driver transistor, said fourth and fifth transistor forming an inverter for controlling said second transistor.
Claim 3
Dependent Claim
20 words
A circuit according to claim 1 wherein said second transistor has a conductivity opposite to that of said driver transistor.
Claim 4
Dependent Claim
20 words
A circuit according to claim 2 wherein said third transistor is of the same conductivity type as said driver transistor.
References Cited (Backward Citations)
US3109943A
Cited
US3700981A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |