High sensitivity charge-transfer sense amplifier

A balanced charge-transfer sense amplifier for one-device cell memory arrays is presented. Charge-transfer techniques are used to preamplify the sense signal and to isolate the large bit/sense (B/S) line capacitance from the nodes of a dynamic latch. The high sensitivity of the sense-refresh amplifier is demonstrated in an experimental memory array with a B/S line to ell storage node capacitance ratio of 40 and a sense signal of about 61 mV. Performance limitations are also discussed.