2Kbit serial EEPROM with Microwire — the 5V-only workhorse
The Microchip 93C56B-I/SN is a 2Kbit non-volatile serial EEPROM using the Microwire interface, organized as 128 x 16 bits. The 2 MHz clock frequency supports moderate-speed parameter storage — calibration constants, configuration tables, or serial-number retention — without the overhead of an SPI or I2C bus.
Write cycle timing and endurance planning
For a 128-word device, a full-chip rewrite takes about 256 ms — acceptable for infrequent updates like field firmware parameter changes. The EEPROM technology supports 1 million erase/write cycles typical, with data retention of 200 years, per the family datasheet. No wear-leveling is needed at this density for occasional writes, but avoid cycling the same address at sub-second intervals in production.
The ROHS3 compliance covers EU regulatory requirements for lead-free assembly.