1 Kbit I²C EEPROM in a tiny SC-70-5
The Microchip 24AA01T-I/LT is a 1Kbit serial EEPROM with an I²C interface, organized as 128 x 8 bits. The 400 kHz bus clock and 3500 ns access time are standard for this density class — adequate for configuration storage, calibration constants, and small lookup tables in embedded designs. The SC-70-5 package (also known as SOT-353) is one of the smallest footprints available for a serial EEPROM, suited for space-constrained PCBs in sensors, handheld instruments, and portable devices.
Supply range covers 1.8V to 5V rails without translation
The 1.7V to 5.5V supply range means this part works on a 1.8V nominal rail (down to 1.7V minimum) and also on 3.3V or 5V rails. No external level translator is needed when the MCU runs at 1.8V or 3.3V — the EEPROM accepts the bus voltage directly. The 400 kHz I²C clock is supported across the full voltage range, though at 1.8V you may see slightly higher rise times on the bus; keep the capacitance under 100 pF for reliable operation.
For a BOM engineer, this removes the sourcing risk that comes with obsolescent serial EEPROMs.
Industrial temperature grade for outdoor and factory use
The 5ms write cycle time is typical for I²C EEPROMs at this density — budget for it in the firmware write routine, especially if you are writing multiple bytes in a single page.
SC-70-5 footprint — board area and layout notes
The SC-70-5 (SOT-353) package occupies roughly 2 mm × 2.1 mm, saving board space compared to SOIC-8 or TSSOP-8 alternatives. It is a surface-mount package, so reflow soldering is standard. The 5-pin allocation includes SDA, SCL, Vcc, GND, and a write-protect (WP) pin — no address pins, since this is a single-device bus address. Decouple with a 0.1 µF ceramic close to the Vcc pin; the part draws microamps in standby, so a small cap suffices.