US4404654A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor device system
Assignee: Sharp Corp
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Filing: 1981-01-29
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Granted: 1983-09-13
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Expires: 2001-01-29
Abstract
Abstract A ratioless semiconductor read only memory circuit comprises a plurality of insulated gate field-effect transistors being arranged in the form of a matrix consisting of columns and columns, bit lines of the rows of the transistors connected in parallel a sampling transistor connected in series to each of the rows of the transistors and each of the bit lines, and a row selection circuit connected to the respective bit lines for selecting one of the bit lines. The transistors of said array corresponding to individual bits are of the enhancement type or the depletion type depending on desired logic content.
Inventors
- 👤 Setsufumi Kamuro
- 👤 Yoshifumi Masaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:22
CPC Classifications
G; G11; G11C; G11C17/00; G11C17/08; G11C17/10; G11C17/12; G11C17/123
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
139 words
A semiconductor read only memory circuit comprising: a row by column memory array having field effect transistors serially interconnected source to drain in columns, transistors in corresponding positions of respective columns having their bases interconnected to form address lines, each said transistor representing a bit in memory and being of an enhancement type to represent a first binary logic state and being of a depletion type to represent a second binary logic state; output means for receiving information from each of said columns; first means for selectively sampling desired ones of said columns; and second means for selectively sampling desired ones of said address lines; said first and second means collectively defining a desired bit in memory; the logic state of said transistor representing said bit being determined by whether said transistor is said enhancement type or depletion type.
Claim 2
Dependent Claim
139 words
A semiconductor read only memory circuit comprising: a row by column memory array having field effect transistors serially interconnected source to drain in columns, transistors in corresponding positions of respective columns having their bases interconnected to form address lines, each said transistor representing a bit in memory and being of an enhancement type to represent a first binary logic state and being of a depletion type to represent a second binary logic state; output means for receiving information from each of said columns; first means for selectively sampling desired ones of said columns; and second means for selectively sampling desired ones of said address lines; said first and second means collectively defining a desired bit in memory; the logic state of said transistor representing said bit being determined by whether said transistor is said enhancement type or depletion type.
Claim 3
Dependent Claim
14 words
The circuit of claim 1 wherein said transistors are insulated gate field effect transistors.
Claim 4
Dependent Claim
27 words
The circuit of claim 1 wherein selection of one of said columns causes each transistor in said column not sampled by said second means to become conductive.
Claim 5
Dependent Claim
25 words
The circuit of claim 2 wherein said first means includes an enhancement mode insulated gate field effect transistor connected in series with each said column.
Claim 6
Dependent Claim
13 words
The circuit of claim 2 further comprising means for pre-charging said output line.
Claim 7
Dependent Claim
21 words
The circuit of claim 4 wherein said means for pre-charging includes at least one enhancement mode insulated gate field effect transistor.
Claim 8
Dependent Claim
20 words
The circuit of claim 5 wherein said enhancement mode insulated gate field effect transistor is formed as a P-channel type.
Claim 9
Dependent Claim
24 words
The circuit of claim 3 wherein said enhancement mode insulated gate field effect transistors included in said first means are formed as N-channel types.
Claim 10
Dependent Claim
19 words
The circuit of claim 3 further comprising address decoder means for generating gate signals applied to said address lines.
Claim 11
Dependent Claim
19 words
The circuit of claim 8 wherein said address decoder means is formed of P-channel insulated gate field effect transistors.
Claim 12
Dependent Claim
55 words
The circuit of claim 1 wherein said first means for selectively sampling includes a field effect transistor connected in series with each said column; a bit line connected to the gate of each field effect transistor included in said first means; and column selection means connected to said bit lines for selecting a desired column.
Claim 13
Dependent Claim
32 words
The circuit of claim 10 further comprising address decoder means connected to said first and second means for developing address signals for application to said column selection means and said second means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-12 | 1987-03-14 | 1987-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-12 | 1991-03-14 | 1991-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-12 | 1995-03-14 | 1995-09-13 | $7700.00 | Window Closed / Lapsed |