HIGH SPEED, LOW VOLTAGE NON-VOLATILE MEMORY

摘要

A low voltage EPROM which increases its reading speed by charging a word line to a voltage higher than Vcc during a read operation. Two voltage pumps (17, 18), which alternatively place charge on a word line, receive control signals of opposite phase from a temperature insensitive oscillator (13). The voltage from the two voltage pumps (17, 18) passes through a zero threshold voltage n-type pass device (PAn) to a word line (WL0n-WL3n). The zero threshold voltage n-type pass device (PAn) receives its control signal from a third voltage pump (19). In order to make the low voltage EPROM compatible with standard 5V programmers, each output driving circuit consists of a large output driver (55) used under low voltage Vcc conditions and a smaller output driver (57) used under standard 5V Vcc conditions.