CIRCUIT FOR PUMPING DRAIN VOLTAGE

摘要

PURPOSE: A circuit for pumping drain voltage is provided to decrease a current consumption when operating a program by detecting the number of bit when performing a program in a flash memory cell and adjusting a drain pumping voltage according to the number of a cell. CONSTITUTION: A drain voltage pumping unit(12) for programming memory cells of a memory cell array(11) has a ring oscillator(13) and a pumping unit(14). A detecting unit(15) detects the number of bit which is programmed and outputs a program control signal. A first control signal(S1) is generated when the number of bit is 16 bits. A second control signal(S2) is generated when the number of bit is 12 bits. A third control signal(S3) is generated when the number of bit is 8 bits. A fourth control signal(S4) is generated when the number of bit is 4 bits.