Thin film magnetic memory device with high-accuracy data read structure having a reduced number of circuit elements

A thin film magnetic memory device comprising:

• a plurality of memory cells having an electric resistance according to magnetically written storage data;
• first and second data lines complementary to each other;
• and
• a differential amplifier portion for performing data reading according to a difference between passing currents of said first and second data lines, wherein
• said first and second data lines are electrically coupled, in a data read operation, to a fixed voltage via a selected memory cell among said plurality of memory cells and a reference cell provided as a comparison target of said selected memory cell, respectively;
• and
• said differential amplifier portion includes:
• a current supply circuit arranged between a power supply voltage and first and second nodes for supplying the same operation current to said first and second nodes at least in said data read operation, and
• a current amplifier circuit for electrically coupling said first and second nodes to said first and second data lines, respectively, and converting a passing current difference occurring between said first and second data lines into a voltage difference between said first and second nodes so that each of said first and second data lines may be clamped at a predetermined voltage not exceeding a reference voltage.