8 Kbit EEPROM in a SOT-23-6 — the Microwire workhorse
The Microchip 93AA76AT-I/OT is an 8 Kbit serial EEPROM organized as 1K x 8 bits, communicating over a 3 MHz Microwire bus. The SOT-23-6 package keeps the footprint small — useful when board space is tight, but the fine-pitch leads demand a well-tuned reflow profile and a clean stencil aperture.
3 MHz Microwire — timing budget for the host
At 3 MHz, each bit clocks in 333 ns. The Microwire protocol is a simple synchronous serial interface — three wires (SI, SO, SK) plus chip select. The host firmware must insert a 5 ms write-cycle delay after every word or page write before the next command; polling the DO line for ready/busy is the usual approach. If the host SPI peripheral can be configured for Microwire framing (leading edge data, trailing edge capture), no bit-banging is needed. The 1.8 V minimum supply means the bus levels stay compatible with low-voltage MCUs without a level shifter.
For production BOMs that need a second-source option, the 93LC46CT-I/SN (1 Kbit, same Microwire interface, 2.5 V minimum supply, SOIC-8) is a functional alternative at a lower density — but the 93AA76AT-I/OT's 8 Kbit density and wider 1.8 V floor are the primary fit criteria. No pin-compatible drop-in replacement exists at the same density in SOT-23-6; the 93AA66B-I/MS (4 Kbit, MSOP-8) shares the Microwire protocol but differs in package and organization.