Current offset sense amplifier of a modulated current or current unbalance type for programmable memories

摘要

A circuit employing a modulated-current offset-type or current- unbalance, offset-type sense amplifier for reading programmable memory cells employs loads identical to each other and a differential input pair of transistors of the differential amplifier are "cross-coupled" with said identical loads to realize a latch structure for storing an extracted data. The circuit also employs a pair of pass transistors, and a pair of precharge transistors. The pass transistors connect the differential input transistors to a memory matrix and the precharge transistors charge lines of the memory matrix. By properly sizing and fabricating these transistors, the pass transistors connect the differential input transistors with the memory matrix while the currents provided from the precharge transistors are either nulled or minimized. The circuit utilizes three timing signals for sequentially modifying the configuration of the circuit and defining the following phases: start of a new reading cycle, pre-charging of capacitances associated with bit lines, and equalization of output nodes and line potentials, discrimination phase, reading and storing of the extracted data.