| 摘要 |
PURPOSE: A reference cell program circuit of a flash memory is provided to program a reference cell with a threshold program and to terminate the operation of the circuit when program termination automatically. CONSTITUTION: The reference cell program circuit of the flash memory includes a level shifter(20), a switch(10), a voltage divider(30), a differential amplifier(40) and a controller. The level shifter shifts the level of an input signal. The switch controls the voltage supplied on a drain of the cell according to the output of the level-shifter. The voltage divider divides the voltage formed by current flowing through the cell with a predetermined ratio. The differential amplifier amplifies the difference between the reference voltage and the divided voltage output from the voltage divider according to an adjust signal. The controller logically combines the adjust signal and the output signal of the differential amplifier to control the level shifter.
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