The Microchip AT21CS11 series of 2-pin memory (SI/O and Ground) harvests energy from the SI/O pin to power the integrated circuit. It provides 1,024 bits of Serial EEPROM organized as 128 words of eight bits each. The device is optimized to add configuration and use information in unpowered attachments using a two-point mechanical connection that brings only one signal (SI/O) and GND to the unpowered attachment. The device is available in space‑saving package options and operates with an external pull‑up voltage from 2.7 V to 4.5 V on the SI/O line.

Maximum temperature under bias -55°C to +125°C
Storage temperature -65°C to +150°C
Voltage on any pin with respect to ground -0.6 V to VPUP +0.5 V
DC output current 15.0 mA