Analog Devices Inc./Maxim Integrated DS2433S+T&R

Overview

DS2433S+T&R from Maxim Integrated is a 4Kb 1-Wire® EEPROM IC with factory-lasered 64-bit ROM (8-bit family code 0x23, 48-bit unique serial number, 8-bit CRC), 16 pages × 256-bit EEPROM memory, and 256-bit scratchpad buffer. It operates parasitically from a single data line at 2.8V–6.0V across –40°C to +85°C and supports both standard (16.3kbps) and Overdrive (142kbps) communication modes. It is used for calibration storage, board identification, and product revision tracking in embedded sensor nodes.

For engineers reviewing the DS2433S+T&R datasheet, DS2433S+T&R pinout, DS2433S+T&R application, or DS2433S+T&R equivalent, key selection considerations include its 1-Wire interface compatibility, parasite-power capability, page-based write-verify protocol, SO-8 package footprint, and absence of external V_CC requirement - critical for space-constrained, low-pin-count designs requiring traceable device identity.

Technical Context

The DS2433S+T&R implements a strict 1-Wire hierarchical protocol: bus initialization must precede ROM function commands (e.g., Skip ROM 0xCC or Match ROM 0x55), which then enable memory functions (Write Scratchpad 0x0F, Read Scratchpad 0xAA, Copy Scratchpad 0x55). Its internal address registers (TA1, TA2, E/S) govern scratchpad targeting and transfer status, with E/S providing ending offset and Partial Flag (PF) for integrity validation.

Parasite power operation relies on controlled I/O line timing and pullup resistor selection (1.5kΩ–5kΩ); during Copy Scratchpad execution (≤5ms), bus voltage must remain ≥2.8V. The 8-bit CRC (X⁸+X⁵+X⁴+1) ensures ROM authenticity, while CRC16 (X¹⁶+X¹⁵+X²+1, inverted) verifies scratchpad writes - both computed in hardware without host CPU overhead.

Key Specifications

Pinout & Package

DS2433S+T&R is supplied in an 8-pin SO (Small Outline) surface-mount package (208 mils wide), pin-compatible with industry-standard SOIC-8 footprints. Pin 1 is Ground, Pin 2 is Data (1-Wire I/O), Pins 3–8 are No Connect (NC).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2433S+T&R, DS2431+T&R offers lower cost and footprint compatibility but lacks sufficient memory for complex calibration datasets, while DS28EC20+T&R adds cryptographic security and 5× memory capacity at higher unit cost and firmware complexity - making DS2433S+T&R the optimal balance for industrial ID and moderate calibration storage.

Availability

DS2433S+T&R is available at Aetrix Electronics and suitable for calibration data storage, board-level identification, and product revision tracking requiring stable component supply, long-term obsolescence management, and RoHS-compliant tape-and-reel delivery.

Supply support for DS2433S+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) is a semiconductor company specializing in analog, mixed-signal, and digital ICs for industrial, communications, and computing applications.

The DS2433S+T&R belongs to Maxim's 1-Wire EEPROM product line, designed specifically for low-pin-count, parasitically powered identification and nonvolatile data storage in distributed sensor networks and embedded systems.

FAQ

What is the primary function of the DS2433S+T&R in a system?

The DS2433S+T&R serves as a parasitically powered, single-pin 1-Wire EEPROM that provides guaranteed unique device identity (via 64-bit lasered ROM) and 4Kb of user-programmable nonvolatile memory. Its core function is to store calibration constants, board IDs, and revision metadata in space-constrained embedded systems where minimizing interconnects is critical. The DS2433S+T&R eliminates the need for separate power and address lines, enabling direct connection to a microcontroller GPIO pin.

Does the DS2433S+T&R require an external power supply?

No, the DS2433S+T&R operates entirely from parasite power harvested from the 1-Wire data line - no external V_CC connection is needed. It functions across 2.8V–6.0V with appropriate pullup resistor sizing (1.5kΩ–5kΩ). During Copy Scratchpad operations (≤5ms), the bus voltage must remain ≥2.8V; this is ensured by strong pullup or active drive during write cycles. The DS2433S+T&R's design inherently supports 2-wire cabling (data + ground) in sensor modules and accessories.

How does the DS2433S+T&R ensure data integrity during writes?

The DS2433S+T&R enforces data integrity through a two-stage write process: first, data is written to a 256-bit scratchpad and verified via hardware-generated CRC16 (X¹⁶+X¹⁵+X²+1, inverted) or readback; second, only after verification does the Copy Scratchpad command transfer data to EEPROM. The E/S register reports ending offset and Partial Flag (PF) to detect incomplete writes or power loss. This protocol prevents partial or corrupted writes - a critical reliability feature for DS2433S+T&R in unattended field deployments.

What is the significance of the 64-bit ROM in the DS2433S+T&R?

The 64-bit ROM in the DS2433S+T&R consists of an 8-bit family code (0x23), a unique 48-bit serial number, and an 8-bit CRC - all factory-lasered and permanently unalterable. This provides absolute, collision-free device identity for MicroLAN networks, enabling reliable enumeration of multiple DS2433S+T&R devices on a shared bus. The ROM allows hosts to perform Match ROM or Search ROM operations, making DS2433S+T&R ideal for asset tracking, anti-counterfeiting, and automated calibration management where each unit must be individually addressable and authenticatable.

Is the DS2433S+T&R compatible with other 1-Wire devices on the same bus?

Yes, the DS2433S+T&R is fully compatible with other 1-Wire devices (e.g., DS18B20, DS2401) on the same multidrop bus due to its built-in multidrop controller and adherence to the standardized 1-Wire protocol hierarchy. It responds to standard ROM commands (Skip ROM, Match ROM, Search ROM) and memory functions, allowing coexistence with temperature sensors, iButtons, and other slaves. However, Overdrive mode activation requires coordination across all Overdrive-capable devices, and bus timing must comply with the slowest device's specification - confirming DS2433S+T&R interoperability in mixed-node MicroLAN systems.