Analog Devices Inc./Maxim Integrated DS2405/T&R

Overview

DS2405/T&R from Maxim Integrated is an addressable 1-Wire® open-drain N-channel switch with factory-lasered 64-bit ROM (8-bit family code 05h, 48-bit serial number, 8-bit CRC), 4mA PIO sink capability at 0.4V, operation from 2.8V to 6.0V across -40°C to +85°C, and support for multidrop MicroLAN networks. It enables remote on/off control and state sensing of individual nodes in distributed sensor or access-control systems.

For engineers reviewing the DS2405/T&R datasheet, DS2405/T&R pinout, DS2405/T&R application, or DS2405/T&R equivalent, this page delivers verified electrical specs, TO-92 package mapping, 1-Wire protocol timing constraints, PIO control logic behavior, and validated alternatives for industrial node addressing and parasitic-powered switching.

Technical Context

The DS2405/T&R implements a parasitically powered 1-Wire slave device with embedded ROM search and match algorithms, enabling bus masters to uniquely identify and toggle individual devices on a shared multidrop line. Its internal circuitry includes a 1-Wire interface controller, CRC generator, and open-drain N-MOSFET output stage with no external bias required.

Communication follows Dallas Semiconductor's standard 1-Wire protocol: initialization via reset/presence pulses, ROM function commands (Match ROM 55h, Search ROM F0h, Active-Only Search ECh), and bidirectional data transfer using time-slot–based write-0/write-1/read-data signaling with strict timing windows (tSLOT = 60–120μs, tLOWR = 1–15μs).

Key Specifications

Pinout & Package

DS2405/T&R is supplied in TO-92 tape-and-reel packaging. The TO-92 package has three leads: Pin 1 (Ground), Pin 2 (Data), Pin 3 (PIO). Leads are formed to 100 mil (2.54 mm) spacing per drawing 56-G0006-003.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2405/T&R, DS2413/T&R trades parasitic operation for dual outputs and stable VDD-supplied drive, while DS2406/T&R extends functionality with EEPROM without sacrificing power architecture - both retain full 1-Wire compatibility and TO-92 mechanical fit.

Availability

DS2405/T&R is available at Aetrix Electronics and suitable for access control systems, industrial sensor networks, asset tracking tags, and smart building HVAC zones requiring stable component supply, long-term lifecycle support, and consistent tape-and-reel delivery for automated assembly.

Supply support for DS2405/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, communications, computing, and consumer applications.

The DS2405/T&R belongs to Maxim's 1-Wire addressable switch product line, engineered specifically for parasitically powered, uniquely identifiable node control in distributed MicroLAN systems where wiring minimization and device-level security are critical.

FAQ

What is the primary function of the DS2405/T&R in a 1-Wire network?

The DS2405/T&R functions as an addressable open-drain N-channel switch that enables remote on/off control and state sensing of individual nodes via the 1-Wire bus. Each DS2405/T&R contains a unique 64-bit ROM for identification, and its PIO pin can be toggled or read using Match ROM or Search ROM commands - all without requiring a dedicated power supply due to parasitic operation. This makes DS2405/T&R ideal for distributed control points where wiring and power delivery are constrained.

Does DS2405/T&R require an external power supply?

No, DS2405/T&R operates exclusively on parasitic power harvested from the 1-Wire bus. It stores energy on an internal capacitor during high bus periods and uses that stored charge to power internal logic and drive the PIO output during low periods. No VCC connection is needed - only Ground (Pin 1), Data (Pin 2), and PIO (Pin 3) are used. This eliminates the need for local regulators or power traces, simplifying design for battery-free or hard-to-wire installations.

What package type is used for DS2405/T&R?

DS2405/T&R is supplied in the TO-92 through-hole package in tape-and-reel format. The TO-92 variant has three leads: Pin 1 (Ground), Pin 2 (Data), and Pin 3 (PIO), with leads formed to 100 mil (2.54 mm) spacing per mechanical drawing 56-G0006-003. This compact, low-cost package supports manual or automated assembly and is compatible with legacy 1-Wire infrastructure.

How does DS2405/T&R ensure device uniqueness in a multidrop network?

DS2405/T&R ensures absolute uniqueness via a factory-lasered 64-bit ROM consisting of an 8-bit family code (05h), a cryptographically unique 48-bit serial number, and an 8-bit cyclic redundancy check (CRC). No two DS2405/T&R units share the same ROM - each is individually tested and programmed during manufacturing. This allows unambiguous identification, secure addressing, and collision-free operation even when hundreds of DS2405/T&R devices share a single 1-Wire bus.

Can DS2405/T&R be used alongside other 1-Wire devices like DS18B20 on the same bus?

Yes, DS2405/T&R is fully compatible with other MicroLAN devices including DS18B20 temperature sensors, DS1990A iButtons, and DS2438 smart batteries. Its built-in multidrop controller adheres strictly to the Dallas Semiconductor 1-Wire protocol, supporting standard ROM function commands and timing. Bus masters can interleave DS2405/T&R PIO control with DS18B20 temperature reads using Match ROM and Skip ROM commands - enabling mixed-function sensor+actuator networks on a single wire.