Analog Devices Inc./Maxim Integrated DS2502R+T&R

Overview

DS2502R+T&R from Maxim Integrated is a 1k-bit add-only memory IC with factory-lasered 64-bit ROM ID, 1-Wire interface, and SOT-23-3 package. It provides absolute traceability via guaranteed unique serial number, supports page-level write protection, and operates from 2.8V to 6.0V across –40°C to +85°C for asset tracking and calibration storage in industrial sensors and medical devices.

For engineers reviewing the DS2502R+T&R datasheet, DS2502R+T&R pinout, DS2502R+T&R application, or DS2502R+T&R equivalent, key selection considerations include parasitic power operation, 12V programming voltage requirement, 3-pin SOT-23 footprint compatibility, and EPROM page redirection capability for firmware patching without physical replacement.

Technical Context

The DS2502R+T&R implements a 1-Wire slave architecture with parasitic power harvesting - deriving all operating energy from the data line during high periods and sustaining operation via internal capacitor discharge. Its hierarchical command protocol requires ROM function commands (e.g., Read ROM, Skip ROM) before accessing memory functions like Read Memory (F0h) or Write Memory (0Fh).

It integrates three core memory regions: 64-bit lasered ROM (8-bit family code 09h + 48-bit serial + 8-bit CRC), 1024-bit EPROM partitioned into four 256-bit pages, and 64-bit EPROM status bytes for write protection and page address redirection. Bit-level programming allows only 1→0 transitions; page invalidation is managed via one's complement redirection bytes.

Key Specifications

Pinout & Package

SOT-23-3 package: compact 3-pin surface-mount outline with exposed pad not electrically connected; designed for automated placement and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2430A+T&R and DS28EC20+T&R, the DS2502R+T&R delivers lowest-cost, highest-assurance device identity through factory-lasered ROM and irreversible EPROM - ideal where data immutability and supply-chain traceability outweigh rewrite flexibility or crypto features.

Availability

DS2502R+T&R is available at Aetrix Electronics and suitable for industrial sensor tagging, medical device calibration storage, and access control token applications requiring stable component supply and long-term lifecycle continuity.

Supply support for DS2502R+T&R 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.

The DS2502R+T&R belongs to Maxim's 1-Wire memory product line, engineered specifically for low-pin-count, parasitic-powered traceability in space-constrained and cost-sensitive embedded systems.

FAQ

What is the programming voltage requirement for DS2502R+T&R?

The DS2502R+T&R requires a 11.5V–12.0V programming pulse applied to the DATA line for 480 µs to program EPROM bits. This high-voltage pulse is generated externally by the bus master; the DS2502R+T&R detects it via an internal high-voltage detect circuit. Read operations use standard 2.8V–6.0V supply derived parasitically from the same line.

Does DS2502R+T&R support true random-access writes to any memory location?

No. The DS2502R+T&R supports only add-only programming: bits transition from 1 to 0, never reversed. Writing to a specific address requires loading data into the 8-bit scratchpad first, verifying its CRC, then applying the 12V pulse. Each write affects one byte at a time, and pages must be redirected via status bytes to logically replace outdated data.

How is device uniqueness guaranteed in DS2502R+T&R?

Each DS2502R+T&R contains a factory-lasered 64-bit ROM with an 8-bit family code (09h), 48-bit globally unique serial number, and 8-bit CRC computed over the first 56 bits. This ROM is tested and guaranteed at wafer sort - no two DS2502R+T&R devices share the same ID, enabling absolute traceability in regulated environments.

Can DS2502R+T&R operate without an external power supply?

Yes. The DS2502R+T&R operates entirely on parasitic power harvested from the 1-Wire DATA line during high periods. An internal capacitor stores energy to sustain operation during low periods. No external V_CC connection is needed - only DATA and GND pins are required for full read functionality.

What package type does DS2502R+T&R use, and are there layout constraints?

The DS2502R+T&R uses a RoHS-compliant SOT-23-3 package with pin 1 = DATA and pins 2 & 3 = GND. Its 3-pin footprint supports standard reflow soldering; unlike SFN variants, it is not limited to electro-mechanical contact use. Layout requires a 4.7kΩ pullup resistor on the DATA line and proper grounding for noise immunity during 1-Wire signaling.