Single-wire EEPROM for pin-constrained designs
The Microchip 11LC020-I/SN is a 2 Kbit serial EEPROM that communicates over a single-wire interface, needing only one I/O pin plus ground to read and write. Organized as 256 x 8 bits, it stores configuration parameters, calibration constants, or serial numbers in designs where every GPIO counts — think sensor modules, compact IoT nodes, or small-form-factor industrial controls. The single-wire bus runs at 100 kHz, which is slower than SPI or I2C but often fast enough for infrequent parameter updates.
That same wide margin covers mixed-voltage systems where the MCU runs at 3.3 V but legacy peripherals still use 5 V.