CIRCUIT FOR PUMPING DRAIN VOLTAGE

摘要

PURPOSE: A circuit for pumping a drain voltage is provided to prevent the deterioration of a program by obtaining a predetermined pumping voltage through improving an oscillator output. CONSTITUTION: A voltage detect circuit(41) detects a drain voltage from an output terminal(OUT) lower than a regulation voltage. A second voltage compare circuit(46) compares a voltage(V11) from the voltage detect circuit with a second control voltage(V12) regulated in a voltage adjust circuit(43). The second voltage compare circuit outputs a fourth control voltage(V14) of high state to an oscillator(31) for raising the output of the oscillator. Therefore, the output of the oscillator is increased for uniformly outputting the drain voltage through the output terminal regardless of the change in a source voltage.