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 IC 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, operates from 2.8V to 6.0V across –40°C to +85°C, and communicates at up to 16.3kbits/s using parasitic power only - used for node-level identification and remote control in distributed sensor networks and 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/SOT-223/TSOC package mapping, 1-Wire ROM command behavior, PIO sensing/toggling logic, and real-world MicroLAN deployment considerations - all grounded in Maxim's official DS2405 datasheet Rev. 071107.

Technical Context

The DS2405 implements a slave-only 1-Wire interface with embedded multidrop controller logic, enabling bus masters to uniquely identify and individually toggle or sense the PIO state of multiple devices on a single bidirectional line. Its 64-bit ROM supports Read ROM, Match ROM, Search ROM, Active-Only Search ROM, and Skip ROM commands - though Skip ROM has no functional effect due to absence of additional memory.

Operation relies entirely on parasitic power harvested from the 1-Wire bus via internal capacitor storage; no external V_CC is required. The PIO pin functions as an open-drain N-channel MOSFET output with ≥4mA sink current at 0.4V, and its logic level is readable over the same 1-Wire bus using read time slots - enabling closed-loop control without added signal lines.

Key Specifications

Pinout & Package

DS2405+T&R is supplied in TO-92 tape-and-reel packaging. Pin assignments are identical across TO-92, SOT-223, and TSOC variants per Maxim's mechanical drawings.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2405+T&R, DS2413+T&R offers expanded I/O density at the cost of increased complexity and footprint, while DS2406+T&R retains full pin and protocol compatibility but adds EEPROM for configuration persistence - making it a drop-in upgrade for applications needing local data storage without changing layout or firmware timing.

Availability

DS2405+T&R is available at Aetrix Electronics and suitable for industrial sensor networks, secure access tokens, distributed power monitoring, and legacy system retrofit interfaces requiring stable component supply and long-term lifecycle support.

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, automotive, communications, and computing applications - emphasizing reliability, integration, and low-power operation.

The DS2405+T&R belongs to Maxim's 1-Wire addressable switch product line, engineered specifically for distributed identification and control in resource-constrained MicroLAN environments where minimal wiring, parasitic power, and absolute device uniqueness are mandatory design requirements.

FAQ

What is the function of the PIO pin on the DS2405+T&R?

The PIO pin on the DS2405+T&R is an open-drain N-channel MOSFET output capable of sinking ≥4mA at 0.4V. It is remotely controlled via 1-Wire Match ROM or Search ROM commands and its logic state (high/low) can be read back over the same bus - enabling both actuation and status verification without additional signal lines. This dual capability makes DS2405+T&R ideal for closed-loop node control in MicroLAN architectures.

Does the DS2405+T&R require an external power supply?

No, the DS2405+T&R operates exclusively on parasitic power harvested from the 1-Wire bus through its DATA pin. An internal capacitor stores charge during high bus periods and powers the device during low periods - eliminating the need for V_CC connections. This feature is fundamental to DS2405+T&R's use in ultra-low-power and space-constrained applications like embedded sensors and access tokens.

How does the DS2405+T&R ensure unique device identification?

The DS2405+T&R contains a factory-lasered 64-bit ROM comprising an 8-bit family code (05h), a unique 48-bit serial number, and an 8-bit CRC - all permanently programmed and tested. No two DS2405+T&R units share the same ROM, guaranteeing absolute identity. This structure enables reliable device enumeration, collision-free addressing, and secure node authentication in multidrop 1-Wire networks.

Can multiple DS2405+T&R devices share the same 1-Wire bus?

Yes, multiple DS2405+T&R devices can coexist on a single 1-Wire bus. The built-in multidrop controller and standardized 1-Wire protocol allow individual addressing via Match ROM or selective enumeration via Search ROM. Each DS2405+T&R responds only to commands matching its unique 64-bit ROM, enabling independent PIO control and status reporting - a core capability confirmed in Maxim's DS2405+T&R datasheet Rev. 071107.

What package options are available for the DS2405+T&R?

The DS2405+T&R is supplied in TO-92 tape-and-reel packaging, as indicated by the "T&R" suffix. Maxim also offers the same silicon die in SOT-223 (DS2405Z/T&R) and 6-pin TSOC (DS2405P/T&R) packages - all sharing identical pin functions (GND, DATA, PIO) and electrical specifications. TO-92 remains the most widely used variant for through-hole prototyping and compact industrial modules.