Sense amplifier
AssigneeInternational Business Machines Corporation
InventorsCui Li Chen, Xiao Li Hu, Qing Q L Li, Rui Tu
Life of this patent
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Abstract
Embodiments of the invention provide a sense amplifier, a SRAM chip comprising the sense amplifier and a method for conducting read operation on a SRAM cell. The sense amplifier according to an embodiment of the invention comprises a cross coupling circuit, a tail current transistor and an output stage, wherein source of the tail current transistor is connected to a negative level. With the scheme according to embodiments of the invention, speed of the sense amplifier can be enhanced, thereby increasing read speed of the SRAM chip.
Claims8
A sense amplifier, comprising:
- a first transistor, a second transistor, a third transistor, a fourth transistor, a tail current transistor and an output stage:
- wherein, gate of the second transistor and gate of the fourth transistor are connected to two inputs of the sense amplifier respectively, gate of the third transistor, drains of the first transistor and the second transistor are connected at a second node, gate of the first transistor, drains of the third transistor and the fourth transistor are connected at a first node, sources of the first transistor and the third transistor are connected to an power supply level, sources of the second transistor and the fourth transistor are connected to drain of the tail current transistor, gate of the tail current transistor is connected to a sense amplifier enabling signal, source of the tail current transistor is connected to a negative level, and the first node and the second node are connected to the output stage respectively,
- wherein the negative level is supplied from a negative voltage output node of a bootstrap circuit.
A method for conducting read operation on a SRAM cell, comprising:
- connecting a bit line of the SRAM cell to an input of a sense amplifier;
- enabling a bootstrap circuit connected to source of a tail current transistor of the sense amplifier, such that a negative voltage output node of the bootstrap circuit outputs a negative voltage to the source of the tail current transistor;
- enabling the sense amplifier, so as to read the logic value stored in the SRAM cell.
Dependencies are inferred from the claim text.