Power efficient read circuit for a serial output memory device and method

Abstract

An integrated circuit memory device has a plurality of memory cells arranged in a plurality of arrays. Each array has a plurality of rows, and a plurality of column lines, and a plurality of row lines connecting to the memory cells in each array. The memory cell in an array is addressable by a column line and a row line. A column address decoder receives a column address signal and selects one or more column lines of each array in response. A row address decoder receives a row address signal and selects a row line of each array in response. The memory device also has a plurality (k) of sense amplifiers, with one sense amplifier associated with each array, connectable to one or more column lines of the array and receives a signal therefrom supplied from an addressed memory cell. The memory device further has a register; and a control circuit. The control circuit receives a read command, and a clock signal, and in response to the read command activates a first plurality (j) of the plurality (k) of sense amplifiers (j<k) for a time period sufficient to sense the signal on a connected column line associated with each of the plurality (j) of sense amplifiers. The control circuit latches the signal into the register; and deactivates the first plurality (j) of sense amplifiers; and serially outputs the signal from the register in response to the clock signal.