The AT27BV040 chip is a high performance, low power, low voltage, 4,194,304-bit one-time programmable read only memory (EPROM) organized as 512K by 8 bits. It requires only one supply in the range of 2.7 to 3.6V in normal read mode operation, making it ideal for fast, portable systems using either regulated or unregulated battery power. Atmel’s innovative design techniques provide fast speeds that rival 5V parts while keeping the low power consumption of a 3V supply. At VCC = 2.7V, any byte can be accessed in less than 100 ns. With a typical power dissipation of only 18 mW at 5 MHz and VCC = 3V, the AT27BV040 consumes less than one fifth the power of a standard 5V EPROM. Standby mode supply current is typically less than 1 µA.