The SST28SF/VF040A are 512K x8 bit CMOS SectorErase, Byte-Program EEPROMs. The SST28SF/VF040A are manufactured using SST's proprietary, high performance CMOS SuperFlash EEPROM Technology. The split-gate cell design and thick oxide tunneling injector attain better reliability and manufacturability compared with alternative approaches. The SST28SF/VF040A erase and program with a single power supply. The SST28SF/ VF040A conform to JEDEC standard pinouts for byte wide memories and are compatible with existing industry standard flash EEPROM pinouts. Featuring high performance programming, the SST28SF/ VF040A typically Byte-Program in 35 s. The SST28SF/ VF040A typically Sector-Erase in 2 ms. Both Program and Erase times can be optimized using interface features such as Toggle bit or Data# Polling to indicate the completion of the Write cycle. To protect against an inadvertent write, the SST28SF/VF040A have on chip hardware and Software Data Protection schemes. Designed, manufactured, and tested for a wide spectrum of applications, the SST28SF/ VF040A are offered with a guaranteed sector endurance of 10,000 cycles. Data retention is rated greater than 100 years.