AT21CS01/AT21CS11 Single-Wire, I/O Powered 1-Kbit (128 x 8) Serial EEPROM with a Unique, Factory-Programmed 64-Bit Serial Number Features LowVoltage Operation: AT21CS01 is self-powered via the 1.7V to 3.6V pull up voltage on the SI/O line AT21CS11 is self-powered via the 2.7V to 4.5V pull up voltage on the SI/O line Internally Organized as 128 Words of Eight Bits Each (1-Kbit) 2 Single-Wire Serial Interface with I C Protocol Structure: Device communication is achieved through a single I/O pin Standard Speed and High-Speed Mode Options: 15.4 kbps maximum bit rate in Standard Speed mode (AT21CS01 only) 125 kbps maximum bit rate in High-Speed mode (AT21CS01 and AT21CS11) 8Byte Page Write or Single Byte Writes Allowed Discovery Response Feature for Quick Detection of Devices on the Bus ROM Zone Support: Device is segmented into four 256 bit zones, each of which can be permanently made readonly (ROM) 256 bit Security Register: Lower eight bytes contains a factory-programmed, read-only, 64 bit serial number that is unique to all Microchip single wire products Next eight bytes are reserved for future use and will read FFh Upper 16 bytes are user programmable and permanently lockable SelfTimed Write Cycle (5 ms maximum) Manufacturer Identification Register: Device responds with unique value for Microchip as well as density and revision information High Reliability: Endurance: 1,000,000 write cycles Data retention: 100 years IEC 61000-4-2 Level 4 ESD Compliant (8 kV Contact, 15 kV Air Discharge) Green (Lead-free/Halide-free/RoHS Compliant) Package Options Die Sale Options in Wafer Form and Tape and Reel Packages 2-pad XSFN, 3-lead SOT23, 8-lead SOIC and 4-ball thin WLCSP. Datasheet DS20005857A-page 1 2017 Microchip Technology Inc. AT21CS01/AT21CS11 Package Types (not to scale) 8-lead SOIC 4-ball WLCSP (Top View) (Top View) 3-lead SOT23 2-pad XSFN (Top View) NC 1 8 NC (Top View) SI/O A1 A2 NC 2 NC NC 2 7 NC 1 SI/O GND 3 NC 3 6 NC B1 B2 GND NC 2 GND 1 SI/O GND 4 5 SI/O Description The AT21CS01/11 is a 2-pin memory (SI/O signal and Ground) that harvests energy from the signal pin to power the integrated circuit. It provides 1,024 bits of Serial Electrically Erasable and Programmable Read- Only Memory (SEEPROM) 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. Some unpowered attachment application examples include analog sensor calibration data storage, ink and toner printer cartridge identification, and management of after market consumables. The devices software addressing scheme allows up to eight devices to share a common single wire bus. The device is available in spacesaving package options and operates with an external pull up voltage from 1.7V to 3.6V on the SI/O line (AT21CS01) or from 2.7V to 4.5V on the SI/O line (AT21CS11). DS20005857A-page 2 Datasheet 2017 Microchip Technology Inc.