Analog Devices Inc./Maxim Integrated DS2502X1

Overview

DS2502X1 from Maxim Integrated is a 1-Wire add-only memory IC with factory-lasered 64-bit ROM ID, 1024-bit EPROM (4 × 256-bit pages), page-level write protection, and parasitic power operation. It serves as a tamper-resistant traceability tag for calibration data, asset tracking, and maintenance records in industrial and embedded systems.

For engineers reviewing the DS2502X1 datasheet, DS2502X1 pinout, DS2502X1 application, or DS2502X1 equivalent, this device requires 12V programming pulses, supports 16.3kbps 1-Wire communication, operates from 2.8V–6.0V at –40°C to +85°C, and uses a single DATA/GND interface - critical for space-constrained, low-pin-count designs.

Technical Context

The DS2502X1 implements a hierarchical 1-Wire protocol: ROM function commands (e.g., Read ROM, Skip ROM) must be executed first to access memory functions. Its internal architecture includes an 8-bit scratchpad buffer, on-chip 8-bit CRC generator, and program-voltage detection circuitry that triggers only during 12V pulses.

EPROM programming follows a strict bit-wise 1→0 transition rule; no bit can be reset from 0 to 1. Page Address Redirection Bytes (in Status Memory) enable software-level data patching by mapping invalid pages to replacement pages - a key enabler for field-updatable calibration or revision data without physical replacement.

Key Specifications

Pinout & Package

DS2502X1 is packaged in a 4-terminal Wafer-Level Package (WLP), qualified for surface-mount assembly. Pin 1 = DATA (bidirectional 1-Wire I/O), Pins 2A/2B = GND (dual ground terminals for robust return path), and "rrd" laser mark indicates revision/date code. No NC or V_CC pins - power derived entirely from DATA line.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar add-only memory applications.

Compared with DS2502X1, DS2430A offers rewrite flexibility but sacrifices absolute traceability and permanent protection, while DS28EC20 delivers cryptographic assurance at the cost of parasitic power capability and higher integration overhead - making DS2502X1 optimal for cost-sensitive, battery-free, high-integrity logging.

Availability

DS2502X1 is available at Aetrix Electronics and suitable for calibration data storage, asset tracking, firmware revision registry, and access control credential applications requiring stable component supply and long-term industrial lifecycle support.

Supply support for DS2502X1 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, and communications markets - emphasizing reliability, integration, and low-power operation.

The DS2502X1 belongs to Maxim's 1-Wire memory product line, engineered specifically for secure, minimal-footprint device identification and immutable data logging in resource-constrained environments.

FAQ

What is the primary function of the DS2502X1 in a system?

The DS2502X1 serves as a secure, add-only memory node with guaranteed unique identity. It stores calibration data, asset history, or firmware metadata using its 1024-bit EPROM and factory-lasered 64-bit ROM ID. Its 1-Wire interface enables direct microcontroller connection with no external power - making DS2502X1 ideal for retrofitting legacy equipment or embedding in space-constrained sensors.

How does the DS2502X1 achieve tamper resistance?

The DS2502X1 achieves tamper resistance through three mechanisms: (1) permanent per-page write protection bits in status memory, (2) irreversible 1→0 bit programming - preventing restoration of erased data, and (3) factory-lasered 64-bit ROM ID with embedded CRC, which cannot be altered post-manufacture. These features ensure DS2502X1 remains a trusted source for calibration constants and access credentials even in unsecured physical environments.

Can the DS2502X1 be reprogrammed multiple times?

Yes, the DS2502X1 supports multiple programming cycles - but only in add-only mode: new data can be written to unused bits (1→0 transitions), and obsolete pages can be logically invalidated using Page Address Redirection Bytes. However, once a bit is programmed to '0', it cannot revert to '1'. So DS2502X1 is not rewritable like EEPROM, but its redirection architecture enables effective field updates without physical replacement.

What voltage and timing requirements apply to DS2502X1 programming?

DS2502X1 requires a precise 11.5V–12.0V programming pulse lasting 480 µs on the DATA line - delivered after successful CRC validation of the write command. This high-voltage pulse is generated externally by the bus master; reads operate at standard 2.8V–6.0V levels. The DS2502X1's internal voltage-detect circuit confirms pulse presence before enabling EPROM programming - ensuring DS2502X1 only commits data when conditions meet specification.

Is the DS2502X1 compatible with standard 1-Wire microcontroller libraries?

Yes, the DS2502X1 fully complies with the standard 1-Wire protocol stack: it responds to ROM Function Commands (Read ROM, Skip ROM) and supports Memory Function Commands (Read Memory, Write Memory, Read Status, etc.) with LSB-first bit ordering and built-in 8-bit CRC. Standard Maxim/Analog Devices 1-Wire drivers - including those for Arduino, STM32, and PIC - natively support DS2502X1 without modification, provided the host can generate the required 12V programming pulse.