Circuits and methods for amplification of electrical signals

Abstract

An amplifier used in some embodiments as a sense amplifier for a memory includes a plurality of first sense amplifiers 220.i whose outputs are connected to high capacitance nodes SA, SA which in turn are connected to inputs of second sense amplifier 240. The state of nodes SA, SA is defined by the currents on the two nodes. The voltages on nodes SA, SA, however, are kept substantially constant, which increases the state switching speed and reduces the power consumption. When the amplifier is not in use and the power-down circuitry reconfigures the amplifier to reduce the power consumption, the second amplifier 240 places its output OUT2 into a valid state in order to prevent oscillations of the output and to reduce power consumption. When the amplifier returns from the power-down mode, the output OUT2 is kept in that state until nodes SA, SA and certain other nodes within the first and second amplifiers settle to proper current and voltage values. As a result, during settling the oscillations on output OUT are prevented and power consumption is reduced.