Patent ID: 7411830

Claim:
A nonvolatile semiconductor memory device comprising: a memory cell array having memory cells arranged in a matrix form, a read circuit configured to read data from a memory cell in the memory cell array, a program circuit configured to program data into the memory cell in the memory cell array, a read voltage generating circuit configured to generate and supply a read voltage to the read circuit, the read voltage generating circuit including a first constant current source which is connected to an output terminal and supplies a first constant current substantially independent of a temperature variation to the output terminal or discharges the first constant current from the output terminal, a first temperature-dependent current source which is connected to the output terminal and supplies a first temperature-dependent current depending on a temperature variation to the output terminal or discharges the temperature-dependent current from the output terminal, and a current/voltage converter connected to the output terminal, a memory circuit configured to store information used to change a temperature characteristic of the memory cell in the memory cell array, and a switching circuit configured to switch temperature dependency of the read voltage generated by the read voltage generating circuit based on information stored in the memory circuit.