ON Semiconductor Is Now To learn more about onsemi, please visit our website at www.onsemi.com onsemi andand other names, marks, and brands are registered and/or common law trademarks of Semiconductor Components Industries, LLC dba onsemi or its affiliates and/or subsidiaries in the United States and/or other countries. onsemi owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of onsemi product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf. onsemi reserves the right to make changes at any time to any products or information herein, without notice. The information herein is provided as-is and onsemi makes no warranty, representation or guarantee regarding the accuracy of the information, product features, availability, functionality, or suitability of its products for any particular purpose, nor does onsemi assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. Buyer is responsible for its products and applications using onsemi products, including compliance with all laws, regulations and safety requirements or standards, regardless of any support or applications information provided by onsemi. Typical parameters which may be provided in onsemi data sheets and/ or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including Typicals must be validated for each customer application by customers technical experts. onsemi does not convey any license under any of its intellectual property rights nor the rights of others. onsemi products are not designed, intended, or authorized for use as a critical component in life support systems or any FDA Class 3 medical devices or medical devices with a same or similar classification in a foreign jurisdiction or any devices intended for implantation in the human body. Should Buyer purchase or use onsemi products for any such unintended or unauthorized application, Buyer shall indemnify and holdo nsemi and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that onsemi was negligent regarding the design or manufacture of the part. onsemi is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. Other names and brands may be claimed as the property of others. 1 Kb 1-Wire EPROM Add-Only Memory N21C21A Description The N21C21A is a 1K bit serial EPROM containing a factory programmed, unique 48 bit identification number, 8 bit CRC www.onsemi.com generation, and the 8bit family code (09h). A 64bit status register controls write protection and page redirection. The N21C21A 1wire interface requires only a single connection 6 and a ground return. The DATA pin is also the sole power source for the N21C21A. 1 The small surfacemount package options saves printedcircuit SOT23 UDFN6 board space, while the low cost makes it ideal for applications such as SN SUFFIX MU SUFFIX battery pack configuration parameters, record maintenance, asset CASE 527AG CASE 517AP tracking, productrevision status, and accesscode security. Features PIN DESCRIPTIONS 1024 Bits of OneTime Programmable (OTP) EPROM For Storage DQ 1 Of UserProgrammable Configuration Data FactoryProgrammed Unique 64Bit Identification Number 3 VSS SingleWire Interface to Reduce Circuit Board Routing VSS 2 Synchronous Communication Reduces Host Interrupt Overhead No Standby Power Required SOT23 (Top View) 8 byte RAM Buffer (Scratch Pad) Pin Number Pin Description Available in a 3Pin SOT23 1 DQ DATA Serial I/O This is a PbFree Device 2 VSS Applications 3 VSS Security Encoding Inventory Tracking 1 ProductRevision Maintenance DQ VSS BatteryPack Identification UDFN6 (Top View) Pin Number Pin Description 1 Do not connect (NC) 2 DQ DATA Serial I/O 3 Do not connect (NC) 4 Do not connect (NC) 5 VSS 6 Do not connect (NC) ORDERING INFORMATION See detailed ordering and shipping information on page 13 of this data sheet. Semiconductor Components Industries, LLC, 2019 1 Publication Order Number: June, 2020 Rev. 1 N21C21A/D