US Patent 7855909 Calibrating page borders in a phase-change memory

A phase-change memory system includes an array of phase-change memory cells, an amplifier that amplifies a data signal read from a selected one of the phase-change memory cells, and a gain estimation module that adjusts a gain of the amplifier based on a gain parameter that is associated with the selected one of the phase-change memory cells. The gain parameter is based on a number of bits that are represented by the selected one of the phase-change memory cells.