The AT93C46/56/66 provides 1024/2048/4096 bits of serial electrically erasable programmable read-only memory (EEPROM), organized as 64/128/256 words of 16 bits each (when the ORG pin is connected to VCC), and 128/256/512 words of 8 bits each (when the ORG pin is tied to ground). The device is optimized for use in many industrial and commercial applications where low-power and low-voltage operations are essential. The AT93C46/56/66 is available in space-saving 8-lead PDIP, 8-lead JEDEC SOIC, 8-lead EIAJ SOIC, 8-lead MAP, 8-lead TSSOP, and 8-lead dBGA2 packages.
The AT93C46/56/66 is enabled through the Chip Select pin (CS) and accessed via a three-wire serial interface consisting of Data Input (DI), Data Output (DO), and Shift Clock (SK). Upon receiving a Read instruction at DI, the address is decoded and the data is clocked out serially on the DO pin. The Write cycle is completely self-timed, and no separate Erase cycle is required before Write. The Write cycle is only enabled when the part is in the Erase/Write Enable state. When CS is brought high following the initiation of a Write cycle, the DO pin outputs the Ready/Busy status of the part. The AT93C46/56/66 is available in 2.7V to 5.5V and 1.8V to 5.5V versions.