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US4451907A Expired / Lapsed US ⏱️ 0.0 years remaining

Pull-up circuit for a memory

Assignee: Motorola Solutions Inc
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Filing: 1981-10-26
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Granted: 1984-05-29
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Expires: 2001-10-26
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Abstract

Abstract A pull-up circuit for a memory provides an additional natural transistor between a power supply and diode-connected transistors which reduces the voltage on bit sense lines sufficiently to allow selected column select transistors to turn on prior to a memory cell being enabled. Additional control circuitry further reduces the voltage to the diode-connected transistors when no memory cells have been selected to be enabled to compensate for the reduction in voltage drop across the natural transistor when no current is flowing through it.

Inventors

  • 👤 William J. Donoghue
  • 👤 Rodney C. Tesch

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 05:00
CPC Classifications
G; G11; G11C; G11C7/00; G11C7/12

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 115 words
A memory circuit comprising: a conductor; a plurality of memory cells, each memory cell coupled to said conductor; enabling means for enabling one of said memory cells; a diode-connected transistor coupled between said conductor and a common node; a pull-up transistor having a control electrode coupled to a pull-up signal, a first electrode coupled to the common node, and a second electrode coupled to a first power supply terminal; and pull-up means for providing the pull-up signal at a first predetermined voltage level when a control signal is at a first logic state, and for providing the pull-up signal at a second predetermined voltage level when the control signal is at a second logic state.
Claim 2
Dependent Claim 115 words
A memory circuit comprising: a conductor; a plurality of memory cells, each memory cell coupled to said conductor; enabling means for enabling one of said memory cells; a diode-connected transistor coupled between said conductor and a common node; a pull-up transistor having a control electrode coupled to a pull-up signal, a first electrode coupled to the common node, and a second electrode coupled to a first power supply terminal; and pull-up means for providing the pull-up signal at a first predetermined voltage level when a control signal is at a first logic state, and for providing the pull-up signal at a second predetermined voltage level when the control signal is at a second logic state.
Claim 3
Dependent Claim 154 words
A column pull-up circuit comprising: first and second bit sense-lines; a plurality of memory cells, each memory cell coupled to both bit sense lines; row decoder means for enabling one of said memory cells in response to a row address signal; a first diode-connected transistor coupled between the first bit sense line and a common node; a second diode-connected transistor coupled between the second bit sense line and the common node; a pull-up transistor having a control electrode coupled to a pull-up node, a first electrode coupled to the common node, and a second electrode coupled to a power supply terminal; and pull-up means for providing a pull-up signal at a first voltage level to the pull-up node when a control signal is at a first logic state, and for providing the pull-up signal at a voltage level higher than said first voltage level when the control signal is at a second logic state.
Claim 4
Dependent Claim 154 words
A column pull-up circuit comprising: first and second bit sense-lines; a plurality of memory cells, each memory cell coupled to both bit sense lines; row decoder means for enabling one of said memory cells in response to a row address signal; a first diode-connected transistor coupled between the first bit sense line and a common node; a second diode-connected transistor coupled between the second bit sense line and the common node; a pull-up transistor having a control electrode coupled to a pull-up node, a first electrode coupled to the common node, and a second electrode coupled to a power supply terminal; and pull-up means for providing a pull-up signal at a first voltage level to the pull-up node when a control signal is at a first logic state, and for providing the pull-up signal at a voltage level higher than said first voltage level when the control signal is at a second logic state.
Claim 5
Dependent Claim 16 words
The memory circuit of claim 1 or 2 wherein the pull-up transistor is a natural transistor.
Claim 6
Dependent Claim 111 words
The memory circuit of claim 3 wherein the pull-up means comprises: a first transistor having a first electrode coupled to a second power supply terminal, a gate coupled to a complement of the control signal, and a second electrode coupled to an output node which is where the pull-up signal is provided; a second transistor having a control electrode and a first electrode coupled to the first power supply terminal, and a second electrode coupled to the output node; and a third transistor having a control electrode coupled to the control signal, a first electrode coupled to the output node, and a second electrode coupled to the first power supply terminal.
Claim 7
Dependent Claim 29 words
The memory circuit of claim 4 wherein the first transistor is an enhancement transistor, the second transistor is a natural transistor, and the third transistor is a depletion transistor.
Claim 8
Dependent Claim 163 words
A memory circuit comprising: a column conductor; a plurality of memory cells, each memory cell coupled to said column conductor; a diode-connected transistor coupled between the column conductor and a supply node; a pull-up transistor coupled between the supply node and a first power supply terminal; a bit sense common line; a coupling transistor having a first current electrode coupled to the bit sense common line, a second current electrode coupled to the column conductor, and a control electrode for receiving a decoder signal; and a column decoder having an output for providing the decoder signal to the control electrode of the coupling transistor in response to a predetermined address and a chip enable signal, wherein said column decoder has a chip enable transistor which is coupled between the output and the first power supply terminal and which is activated in response to the chip enable signal for enabling the column decoder to provide the decoder signal in response to the predetermined address.
Claim 9
Dependent Claim 163 words
A memory circuit comprising: a column conductor; a plurality of memory cells, each memory cell coupled to said column conductor; a diode-connected transistor coupled between the column conductor and a supply node; a pull-up transistor coupled between the supply node and a first power supply terminal; a bit sense common line; a coupling transistor having a first current electrode coupled to the bit sense common line, a second current electrode coupled to the column conductor, and a control electrode for receiving a decoder signal; and a column decoder having an output for providing the decoder signal to the control electrode of the coupling transistor in response to a predetermined address and a chip enable signal, wherein said column decoder has a chip enable transistor which is coupled between the output and the first power supply terminal and which is activated in response to the chip enable signal for enabling the column decoder to provide the decoder signal in response to the predetermined address.
Claim 10
Dependent Claim 88 words
The memory circuit of claim 6 further comprising: pull-up means for providing a pull-up signal at a first predetermined voltage level when a control signal is at a first logic state, and for providing the pull-up signal at a second predetermined voltage level when the control signal is at a second logic state; and wherein the pull-up transistor has a first current electrode coupled to the supply node, a second current electrode coupled to the first power supply terminal, and a control electrode for receiving the pull-up signal.
Claim 11
Dependent Claim 116 words
The memory circuit of claim 7 wherein the pull-up means comprises: a first transistor having a first electrode coupled to a second power supply terminal, a gate coupled to a complement of the control signal, and a second electrode coupled to an output node for providing the pull-up signal to the control electrode of the pull-up transistor; a second transistor having a control electrode and a first electrode coupled to the first power supply terminal, and a second electrode coupled to the output node; and a third transistor having a control electrode coupled to the control signal, a first electrode coupled to the output node, and a second electrode coupled to the first power supply terminal.
Claim 12
Dependent Claim 25 words
The memory circuit of claim 6 wherein the coupling and diode-connected transistors are enhancement transistors and the chip enable and pull-up transistors are natural transistors.

References Cited (Backward Citations)

US3936810A Cited
US4291392A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-05-29 1987-11-28 1988-05-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-05-29 1991-11-28 1992-05-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-05-29 1995-11-28 1996-05-29 $7700.00 Window Closed / Lapsed

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