US4086642A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective circuit and device for metal-oxide-semiconductor field effect transistor and method for fabricating the device
Assignee: Hitachi Ltd
•
Filing: 1976-01-13
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Granted: 1978-04-25
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Expires: 1996-01-13
Abstract
Abstract A protective circuit comprises a metal-oxide-semiconductor field effect transistor (MOSFET) to be protected, and a depletion-type MOSFET the gate and source of which are connected to each other and the souce of which is connected to the gate of the MOSFET to be protected, whereby the protective circuit which is suitable for a high-speed operation is completed.
Inventors
- 👤 Isao Yoshida
- 👤 Ryoichi Hori
- 👤 Hiroo Masuda
- 👤 Osamu Minato
- 👤 Jun Etoh
- 👤 Masaaki Nakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:54
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/08; H03K17/081; H03K17/0812; H03K17/08122; H03F; H03F1/00; H03F1/52; H03F1/523; H10; H10D; H10D89/00; H10D89/60; H10D89/601; H10D89/811
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
63 words
A protective circuit for a metal-oxide-semiconductor field effect transistor comprising: an input terminal to which input signals are applied; and a depletion-type metal-oxide-semiconductor field effect transistor the gate and source of which are connected to each other, the source of which is connected to the gate of the transistor to be protected, and the drain of which is coupled to said input terminal.
Claim 2
Dependent Claim
63 words
A protective circuit for a metal-oxide-semiconductor field effect transistor comprising: an input terminal to which input signals are applied; and a depletion-type metal-oxide-semiconductor field effect transistor the gate and source of which are connected to each other, the source of which is connected to the gate of the transistor to be protected, and the drain of which is coupled to said input terminal.
Claim 3
Dependent Claim
41 words
A protective circuit according to claim 1, which further comprises an enhancement-type metal-oxide-semiconductor field effect transistor the gate and source of which are connected to each other and the drain of which is connected to the source of said depletion-type transistor.
Claim 4
Dependent Claim
24 words
A protective circuit according to claim 1, which further comprises a resistor connected between the drain of said depletion-type transistor and said input terminal.
Claim 5
Dependent Claim
34 words
A protective circuit according to claim 1, wherein the resistance between the drain and source is increased during increased voltage applied to said input terminal, such that increased potential of the source is suppressed.
References Cited (Backward Citations)
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US3403270A
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US3508084A
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US4044373A
Cited
US3777216A
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US3947727A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-24 | 1981-10-24 | 1982-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-24 | 1985-10-24 | 1986-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-24 | 1989-10-24 | 1990-04-25 | $7700.00 | Window Closed / Lapsed |