64Kbit parallel EEPROM with 200 ns access — still a live part
The Microchip AT28BV64B-20JU is a 64Kbit (8K x 8) parallel EEPROM in a 32-PLCC (J-Lead) package, built for non-volatile storage in 3.3V systems. Its 200 ns access time keeps it compatible with legacy 8-bit MCU buses and CPLD glue logic without wait-state penalties. The part is listed as Active, so it remains a legitimate new-design choice for sockets that need a byte-wide, in-system-reprogrammable memory.
Supply rail and temperature — 2.7V–3.6V, industrial range
Runs from 2.7V to 3.6V, which is the 3.3V logic rail with margin for brownout. If your legacy design used the 5V AT28C64B, this part will not drop in without a regulator change — the supply is strictly 3.3V max.
Write cycle and programming in the field
Word and page writes complete in 10 ms. That is slow enough that firmware-update routines need to poll the ready/busy pin or insert a delay loop, but fast enough for configuration storage and calibration tables. The parallel interface means any 8-bit MCU or FPGA with a byte-wide bus can program it without an I²C or SPI bit-bang — handy for field upgrades if the socket is accessible.
Package and handling — 32-PLCC, socket-friendly
The 32-PLCC (J-Lead) footprint (13.97x11.43 mm body) is a surface-mount package that also fits production sockets — a real advantage for field-service swaps or firmware development where you want to pull and reprogram without desoldering. The J-Lead form gives good visual solder-joint inspection.
The part is ROHS3 compliant.