Southeast University

Cai Gong

Longxing Shi

Jun Yang

Xinning Liu

Yuan Chen

Na Bai

Hong Chang

Fei Pan

Yifeng Deng

Yingcheng Xia

Jiafeng Zhu

Yue Feng

A circuit for improving process robustness of sub-threshold SRAM memory cells serves as an auxiliary circuit for a sub-threshold SRAM memory cell. The output of the circuit is connected to PMOS transistors of the sub-threshold SRAM memory cell and substrate of PMOS transistors in the circuit. The circuit includes a detection circuit for threshold voltages of the PMOS transistors and a differential input and single-ended output amplifier. The circuit changes the substrate voltage of the PMOS transistors in the sub-threshold SRAM memory cell and the PMOS transistors in the circuit in a self-adapting manner by detecting threshold voltage fluctuations of PMOS and NMOS transistor resulted from process fluctuations and thereby regulates the threshold voltages of the PMOS transistors, so that the threshold voltages of the PMOS and NMOS transistors match. The circuit improves the noise margin of sub-threshold SRAM memory cells and the process robustness of sub-threshold SRAM memory cells.

Circuit for enhancing robustness of sub-threshold SRAM memory cell

Disclosed is a noise current compensation circuit. The circuit is provided with two input and output terminals A and B, and two control terminals CON and CONF. The control terminals control a work mode (work state and pre-charge state) of the compensation circuit. The compensation circuit consists of 7 PMOS transistors and 8 NMOS transistors. In the normal work state, by detecting changes of potential change rate of two signal lines in an original circuit, the noise current compensation circuit automatically enables one end of the original circuit that discharges slowly to discharge a signal more slowly, and enables one end of the original circuit that discharges rapidly to discharge a signal more rapidly, thus eliminating the influence of the noise current on the circuit and providing assistance for correct identification of subsequent circuit signals. The current compensation circuit can be used for an SRAM bit line leakage current compensation circuit, because the existence of a large leakage current on the SRAM bit line leads to the decreasing of a voltage difference between two ends of the bit line, resulting in that a subsequent circuit cannot correctly identify a signal.

Noise current compensation circuit

Growing community of inventors

Jiangsu, China

Cai Gong