Analog Devices Inc./Maxim Integrated DS2502X1#U

Overview

DS2502X1#U from Maxim Integrated is a 1-Wire add-only memory IC with factory-lasered 64-bit ROM ID (Family Code 09h), 1024-bit EPROM partitioned into four 256-bit pages, and page-level write protection - used for asset tracking, calibration storage, and maintenance record logging in industrial and medical devices.

For engineers reviewing the DS2502X1#U datasheet, DS2502X1#U pinout, DS2502X1#U application, or DS2502X1#U equivalent, this device supports parasitic power operation from 2.8V–6.0V, requires 11.5–12.0V programming pulses, delivers guaranteed unique traceability via laser-programmed serial number, and interfaces via single-pin 1-Wire protocol at up to 16.3 kbps.

Technical Context

The DS2502X1#U implements a hierarchical 1-Wire protocol requiring ROM Function Commands (e.g., Read ROM, Skip ROM) before enabling Memory Function Commands (e.g., Write Memory [0Fh], Read Data/Generate 8-bit CRC [C3h]). Its internal architecture includes an 8-bit scratchpad buffer, on-chip 8-bit CRC generator, and parasite power harvesting circuitry.

EPROM programming operates bit-wise (1→0 only), with each byte verified post-pulse via read-back; status bytes control page write-protection and support page address redirection (e.g., FDh → page 2) for software-managed data patching without physical reprogramming.

Key Specifications

Pinout & Package

DS2502X1#U uses a 4-terminal Wafer-Level Package (WLP), qualified for electro-mechanical contact applications. Laser-marked top-side contacts are not visible; pin 1A/1B = DATA, pin 2A/2B = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2430A and DS28EC20, the DS2502X1#U uniquely combines guaranteed factory-unique ID, add-only memory semantics, and page-level write protection - making it optimal for calibration, maintenance, and regulatory traceability where data immutability and minimal interface overhead are primary design constraints.

Availability

DS2502X1#U is available at Aetrix Electronics and suitable for asset tracking, medical device calibration, and industrial sensor node applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

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

The DS2502X1#U belongs to Maxim's 1-Wire memory product line, engineered specifically for secure, low-pin-count identification and immutable data storage in resource-constrained embedded systems.

FAQ

What is the function of the 64-bit ROM ID in DS2502X1#U?

The 64-bit ROM ID in DS2502X1#U consists of an 8-bit family code (09h), 48-bit factory-lasered serial number, and 8-bit CRC - providing guaranteed unique device identity for absolute traceability. This ID is read-only, laser-programmed during manufacturing, and used by 1-Wire bus masters to identify and singulate individual DS2502X1#U devices on shared buses without external addressing logic.

Can DS2502X1#U be reprogrammed multiple times?

Yes, DS2502X1#U supports multiple programming cycles, but only in add-only mode: bits transition from logical 1 to 0, never reversed. New data can be appended to unused EPROM space or replace outdated pages via status-byte-controlled address redirection. Each write requires a 12V programming pulse, and pages can be permanently write-protected after final programming to prevent tampering.

Does DS2502X1#U require an external power supply?

No, DS2502X1#U operates with parasitic power - deriving all energy for read operations from the 1-Wire data line via internal capacitance. Only programming requires an external 11.5–12.0V pulse on the same DATA line. This eliminates the need for a dedicated V_CC pin or power rail, simplifying integration into space- and cost-constrained designs.

What package type does DS2502X1#U use, and how is it mounted?

DS2502X1#U uses a 4-terminal Wafer-Level Package (WLP), marked "X1" in the ordering code. It is designed for electro-mechanical contact applications - not soldering - with laser-marked top-side contacts (1A/1B = DATA, 2A/2B = GND) that interface via spring-loaded pogo pins or compliant interconnects. Mounting requires mechanical retention, not reflow soldering.

How does page address redirection work in DS2502X1#U?

DS2502X1#U uses four Page Address Redirection Bytes in its EPROM Status Memory to invalidate obsolete data pages. For example, writing FDh to the redirection byte for page 1 tells host firmware to read updated data from page 2 (one's complement of FDh). The DS2502X1#U hardware does not auto-redirect - firmware interprets these bytes to route reads, enabling software-managed data patching without reprogramming the original page.