| 摘要 |
<p>PURPOSE: To accurately generate a reference potential during sensing. CONSTITUTION: A bias voltage generation circuit 21 includes a series circuit composed of a magneto-resistance element Ref imitating a memory cell, and a MOS transistor QN3. The MR ratio of the magneto-resistance element Ref is set to be half of the MR ratio of the magnet-resistance element in the memory cell. An adjustment resistance (r) has a resistance value half of the wiring resistance of a bit line. The gate of a step-down MOS transistor QP1 is connected to the gate of a MOS transistor as a sense current source for the bit line, and both MOS transistors constitute a current mirror circuit. When Vbias is outputted, and a constant current flows to the bias voltage generation circuit 21, a sense current equal to this constant current also flow to the bit line. The potential of the bit line is changed according to the state of the magneto- resistance element in the memory cell.</p> |
