Sense amplifier with extended supply voltage range

Abstract

A sense amplifier for a memory includes a comparator and a bit line polarization circuit. The comparator receives a first signal representative of a current flowing through a memory cell and a second signal representative of a reference current. Additionally, the comparator includes a stage in a common source configuration and an active load for the stage, and the bit line polarization circuit provides a polarization voltage level that is independent of the supply voltage level. In a preferred embodiment, the sense amplifier also includes an output stage that improves switching time at high supply voltages. Additionally, there is provided a method for sensing logic levels in a memory device. According to the method, a bit line is polarized at a polarization voltage level, and a first signal representative of a current flowing through a memory cell is compared with a second signal representative of a reference current. The polarization voltage level is independent of the supply voltage level. In one preferred method, the polarization voltage level is generated using a steady current that is externally generated.

Dependencies are inferred from the claim text.