1 Kbit serial EEPROM with a 2 MHz Microwire bus
The Microchip 93C46A-I/SN is a 1 Kbit non-volatile serial EEPROM organized as 128 x 8 bits, accessed over a Microwire interface at clock frequencies up to 2 MHz. The write cycle time for a word or page is 2 ms. Housed in an 8-pin SOIC package, this is a straightforward drop-in for any legacy or new design needing a small-footprint serial parameter store — calibration constants, configuration bytes, or serial-number tokens that survive power loss. The 5 V supply requirement is a fixed constraint; if your board runs at 3.3 V, this part needs a regulator or a level translator.
The Microwire interface is mature and well-understood, which means controller-side driver code is trivial and the bus timing is forgiving — no marginal read issues at 2 MHz with typical board parasitics.
Sourcing and fit for your BOM
Because the part is active and widely used, it is available through multiple independent distribution channels.