| 摘要 |
Resistance of a selected memory cell in a Magnetic Random Access Memory ("MRAM") device is sensed by a read circuit including a direct injection charge amplifier, an integrator capacitor and an analog sense amplifier. The direct injection charge amplifier supplies current to the integrator capacitor while maintaining an equipotential voltage on non-selected memory cells in the MRAM device. As the direct injection charge amplifier applies a fixed voltage to the selected memory cell, the sense amplifier generates an input signal having a transition that is time-delayed according to the voltage on the integrator capacitor; generates a reference signal having a time-fixed transition; and compares a relative occurrence of transitions in the input and reference signals. The relative occurrence indicates whether a logic value of '0' or '1' is stored in the selected memory cell.
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