NONVOLATILE SEMICONDUCTOR MEMORY DEVICE CAPABLE OF ADJUSTING STEP-UP VOLTAGE ACCURATELY AND RAPIDLY, IN WHICH PRODUCTION RATE IS IMPROVED

摘要

PURPOSE: A nonvolatile semiconductor memory device is provided which is capable of adjusting a step-up voltage accurately and rapidly and thus increases fabrication yield. CONSTITUTION: The nonvolatile semiconductor memory device includes a nonvolatile cell circuit(12). According to the nonvolatile cell circuit, a boosting circuit(11) generates a step-up voltage(Vpp) as to the nonvolatile cell circuit by receiving a clock signal(CLK). A voltage divider(14) is connected to the boosting circuit, and generates a number of voltages by dividing the step-up voltage. A selector(15) is connected to the divider, and selects one voltage of them. A reference voltage generation circuit generates a reference voltage(Vref). The first comparator(17) is connected to the selector and the reference voltage generation circuit, and compares the selected voltage with the reference voltage. A gate circuit(13) makes the selected voltage almost equal to the reference voltage by providing the clock signal to the boosting circuit according to an output signal of the first comparator. The second comparator(18) compares the step-up voltage with an expected value(Vppe) provided from the external. A count signal generation circuit(19) generates a count signal(S3) according to the output signal of the first comparator. And a counter(20) changes its own value(N) by receiving the count signal.