Analog Devices Inc./Maxim Integrated DS2502-E64+

Overview

DS2502-E64+ from Maxim Integrated is a 1-Wire IEEE EUI-64 node address chip with factory-lasered 64-bit unique ROM, 768-bit user-programmable OTP-EPROM, single-wire interface, and -40°C to +85°C operating range. It serves as a traceable device identifier in FireWire-compliant systems and embedded asset tagging.

For engineers reviewing the DS2502-E64+ datasheet, DS2502-E64+ pinout, DS2502-E64+ application, or DS2502-E64+ equivalent, key selection factors include its EUI-64 compliance, add-only EPROM architecture, 16.3 kbps communication rate, 2.8V–6.0V read voltage range, and TO-92 package compatibility with microcontroller GPIOs.

Technical Context

The DS2502-E64+ implements a 1-Wire bus protocol with presence detection, CRC16 (inverted, polynomial X¹⁶+X¹⁵+X²+1) validation, and multidrop capability. Its ROM contains a fixed 64-bit EUI-64 address (006035h company ID + 40-bit extension ID) and a unique 64-bit registration number used for bus enumeration.

Memory is organized into a write-protected 32-byte page (00h–1Fh) holding the EUI-64 data structure (length byte, Project ID 00001128h, EUI-64, inverted CRC), and a user-programmable 96-byte region (20h–7Fh). Programming requires 11.5V–12.0V at -40°C to +50°C; reads function down to 2.8V across full temperature range.

Key Specifications

Pinout & Package

DS2502-E64+ is supplied in a 3-pin TO-92 package (lead-free/RoHS-compliant). Pin 1 = DATA, Pin 2 = GND, Pin 3 = NC (no internal connection). The device operates with parasitic power or optional V_DD, and uses the DATA line for bidirectional communication and presence detection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 1-Wire node identification applications.

Compared with DS2401+, DS2502-E64+ adds 768-bit user-programmable memory for field data logging, while DS2502P-E64+ offers identical functionality in a space-saving TSOC package - enabling choice between through-hole serviceability and SMT scalability without changing firmware or bus topology.

Availability

DS2502-E64+ is available at Aetrix Electronics and suitable for asset tracking, FireWire device identification, secure firmware versioning, and calibration data storage requiring stable component supply and long-term obsolescence support.

Supply support for DS2502-E64+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and digital ICs for industrial, automotive, communications, and computing applications.

The DS2502-E64+ belongs to Maxim's 1-Wire® family of silicon serializers, engineered specifically for low-pin-count, tamper-resistant device identification and small-data storage in constrained embedded environments.

FAQ

What is the primary function of the DS2502-E64+ in a 1-Wire system?

The DS2502-E64+ serves as a factory-programmed IEEE EUI-64 node address chip with 768-bit user-programmable OTP-EPROM. Its primary function is to provide a globally unique, laser-traceable 64-bit ROM address for bus enumeration, while enabling add-only storage of calibration data, firmware versions, or asset history in the user memory region (20h–7Fh). This dual-role capability makes DS2502-E64+ essential for secure, maintenance-free device identification in industrial and FireWire-compliant systems.

Can the DS2502-E64+ be reprogrammed after initial programming?

No, the DS2502-E64+ supports add-only programming: once a bit is programmed from '1' to '0', it cannot be changed back to '1'. The first 32 bytes (00h–1Fh) are permanently write-protected and contain the EUI-64 structure; the remaining 96 bytes (20h–7Fh) allow incremental writes but no erasure. DS2502-E64+ does not support full-memory erase or bit-level rewrites - this design ensures data immutability and traceability in mission-critical applications.

What voltage and temperature conditions are required to program the DS2502-E64+?

Programming the DS2502-E64+ requires a precise 11.5V to 12.0V pulse applied to the DATA pin, with ambient temperature strictly limited to -40°C to +50°C. Reads operate reliably from 2.8V to 6.0V across the full -40°C to +85°C range. Because programming voltage exceeds normal system supply rails, DS2502-E64+ must be programmed in a controlled test environment using dedicated 1-Wire programmers capable of generating the high-voltage pulse - not during standard field operation.

How does the DS2502-E64+ ensure data integrity during read operations?

The DS2502-E64+ ensures data integrity using an inverted 16-bit CRC calculated over the length byte, UniqueWare Project ID (00001128h), and the 64-bit EUI-64 value, per polynomial X¹⁶+X¹⁵+X²+1. This CRC is stored at addresses 0Dh–0Eh (LSB first). Host systems implementing standard 1-Wire APIs (e.g., Dallas Semiconductor/Maxim SDKs) automatically validate this CRC during read - rejecting corrupted or incomplete data before it enters application logic, thereby guaranteeing reliability of DS2502-E64+ node identification.

Is the DS2502-E64+ compatible with standard 1-Wire microcontroller libraries?

Yes, the DS2502-E64+ is fully compatible with standard 1-Wire microcontroller libraries including Maxim's official 1-Wire Software Development Kits and open-source implementations (e.g., OWFS, Arduino OneWire). Its protocol stack adheres to the universal 1-Wire command set (Search ROM, Read ROM, Skip ROM, Read Memory, Write Memory), and its EUI-64 data structure follows the Default Data Structure defined in Application Note 114 - allowing direct integration with existing 1-Wire host firmware without modification for DS2502-E64+.