A low voltage, high-gain current/voltage sense amplifier (ISA/VSA) circuit
with improved read access time is provided herein. According to one
embodiment, the ISA/VSA described herein includes a pair of current
reference branches for generating a pair of reference currents in
response to a pair of differential input signals supplied thereto. The
differential input signals are differential voltages which are converted
to differential currents by the current reference branches. In some
cases, the current reference branches may be used for amplifying and
mirroring the reference currents onto output nodes of the ISA/VSA. In
doing so, the current reference branches may increase the amplification
and improve the performance of the sense amp circuit, even under extreme
mismatch conditions. In addition, positive feedback may be used within
the ISA/VSA design to further increase the amplification and speed of the
sense operation. The improvements described herein may, therefore, be
used to obtain the fast read access times typically associated with
high-speed memory devices.