Elastic power for read margin
View Patent ↗An elastic power header device and methods of operation are provided to improve the read margin of static random access memory (SRAM) cells by increasing read stability, reducing read disturbance and improving the Signal to Noise Margin (SNM) figure of merit. For example, various implementations of an elastic power header device are utilized as programmable resistances to permit the power supply lines to reach a maximum voltage. Allowing the power supply lines to reach the reference voltage allows more flexibility in read margin and read stability. Furthermore, this additional flexibility can be controlled by means for adjusting a voltage. This adjustment voltage can fine-tune the programmable resistances so that the read margin can be more conveniently controlled.
1. The memory device comprising:
a first power supply line;
a second power supply line;
a static random access memory (SRAM) cell comprising a first logic gate and a second logic gate that are cross-coupled, wherein the first power supply line supplies the first logic gate, and the second power supply line supplies the second logic gate; and
an elastic power header device connected between a reference voltage and each one of the first power supply line and the second power supply line; and
a keeper circuit for limiting the difference between the first power supply line and the second power supply line,
wherein the elastic power header device is configured to provide, during a read operation, a first resistance in the first power supply line and a second resistance in the second power supply line, and
wherein at least one of the first and second resistances comprise a programmable resistance.
2. A elastic power header device comprising:
a first conductive path coupled between a reference voltage and a first power supply line;
a second conductive path coupled between the reference voltage and a second power supply line; and
a keeper circuit for limiting a difference between the first power supply line and the second power supply line,
wherein a resistance of one of the first and second conductive paths each comprises a programmable resistance, and
wherein, in response to a read operation, a relative resistance between the first conductive path and the second conductive path is kept within a predetermined range of values.