Radiation hardened six transistor random access memory and memory device
First Claim
1. A radiation hardened storage cell, comprising in combination:
- a first inverter pair comprised of a first PFET and a first NFET coupled in series drain to drain by a resistor whose resistance is an order of magnitude larger than the source to drain resistance of the first PFET;
said first PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion;
a second inverter pair comprised of a second PFET and a second NFET coupled in series drain to drain by a resistor whose resistance is an order of magnitude larger than the source to drain resistance of the second PFET;
said second PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion;
a first pass gate PFET coupled to the gate of said first PFET, the gate of said first NFET, and the P+ drain diffusion of said second PFET; and
a second pass gate PFET coupled to the gate of said second PFET, the gate of said second NFET, and the P+ drain diffusion of said first PFET.
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Accused Products
Abstract
A memory device can include a radiation hardened, static random access memory (SRAM) cell having a first inverter pair including a first PFET and a first NFET coupled in series drain to drain by a resistor whose resistance can be an order of magnitude (i.e., ten times) larger than the source to drain resistance of the first PFET, a second inverter pair including a second PFET and a second NFET coupled in series drain to drain by a resistor whose resistance can be an order of magnitude larger than the source to drain resistance of the second PFET, the first or second PFET can include a P+ drain difflusion in an NWELL where a portion of the gate can overlie the P+ drain diffusion, a first pass gate PFET coupled to the gate of the first PFET, the gate of the first NFET, and the P+ drain diffusion of the second PFET, and a second pass gate PFET coupled to the gate of the second PFET, the gate of the second NFET, and the P+ drain diffusion of the first PFET.
151 Citations
21 Claims
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1. A radiation hardened storage cell, comprising in combination:
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a first inverter pair comprised of a first PFET and a first NFET coupled in series drain to drain by a resistor whose resistance is an order of magnitude larger than the source to drain resistance of the first PFET; said first PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; a second inverter pair comprised of a second PFET and a second NFET coupled in series drain to drain by a resistor whose resistance is an order of magnitude larger than the source to drain resistance of the second PFET; said second PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; a first pass gate PFET coupled to the gate of said first PFET, the gate of said first NFET, and the P+ drain diffusion of said second PFET; and a second pass gate PFET coupled to the gate of said second PFET, the gate of said second NFET, and the P+ drain diffusion of said first PFET. - View Dependent Claims (2, 3)
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4. A radiation hardened storage cell, comprising:
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a first inverter including a first PFET and a first NFET having commonly coupled gates and separate drains, the drain of said first PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; a second inverter including a second PFET and a second NFET having commonly coupled gates and separate drains, the drain of said second PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; first and second resistors coupling the P+ drain diffusions of the first and second PFETs respectively to the drains of the first and second NFETs; a first pass gate PFET having a drain coupled to the commonly coupled gates of said first inverter and the P+ drain diffusion of said second PFET; and a second pass gate PFET having a drain coupled to the commonly coupled gates of said second inverter and the P+ drain diffusion of said first PFET. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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11. A memory device, comprising:
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addressing circuitry; an array of word lines and complementary bit line pairs coupled to the addressing circuitry; a plurality of storage cells located at the intersection of selected word lines and bit line pairs; a sense amplifier coupled to the complementary bit line pairs; and wherein each of said plurality of storage cells comprises; a first inverter including a first PFET and a first NFET having commonly coupled gates and separate source/drain regions, the source/drain region of said first PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; a second inverter including a second PFET and a second NFET having commonly coupled gates and separate source/drain regions, the source/drain region of said second PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; first and second resistors coupling the P+ drain diffusions of the first and second PFETs respectively to the source/drain regions of the first and second NFETs; a first pass gate PFET having a source/drain region coupled to the commonly coupled gates of said first inverter and the P+ drain diffusion of said second PFET; and a second pass gate PFET having a source/drain region coupled to the commonly coupled gates of said second inverter and the P+ drain diffusion of said first PFET.
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12. An apparatus, comprising:
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an electronic system; and a memory device coupled to said electronic system, wherein said memory device includes a radiation hardened storage cell, having; a first inverter including a first PFET and a first NFET having commonly coupled gates and separate source/drain regions, the source/drain region of said first PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; a second inverter including a second PFET and a second NFET having commonly coupled gates and separate source/drain regions, the source/drain region of said second PFET including a P+ drain diffusion in an NWELL with a portion of the gate overlying the P+ drain diffusion; first and second resistors coupling the P+ drain diffusions of the first and second PFETs respectively to the source/drain regions of the first and second NFETs; a first pass gate PFET having a source/drain region coupled to the commonly coupled gates of said first inverter and the P+ drain diffusion of said second PFET; and a second pass gate PFET having a source/drain region coupled to the commonly coupled gates of said second inverter and the P+ drain diffusion of said first PFET. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A method of operating a radiation hardened storage cell comprising:
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sustaining a SEU event particle hit on a node of the storage cell which changes the logic state at the output of an inverter of the storage cell; recovering from a critical charge deposited on the storage cell as a result of the SEU event on the node; and increasing RC delay slowing feedback propagation through cross-coupled inverter pair allowing more time for recovery wherein write cycle time is not appreciably affected. - View Dependent Claims (21)
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Specification