Analog Devices Inc./Maxim Integrated DS2405P/T&R

Overview

DS2405P/T&R from Maxim Integrated is a 1-Wire® addressable 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 uses parasitic power from the 1-Wire bus - deployed in industrial node identification and remote control of discrete loads.

For engineers reviewing the DS2405P/T&R datasheet, DS2405P/T&R pinout, DS2405P/T&R application, or DS2405P/T&R equivalent, this page delivers verified electrical specs, TSOC-6 package mapping, 1-Wire ROM command behavior, PIO sensing/toggling logic, and real-world MicroLAN integration considerations.

Technical Context

The DS2405P/T&R implements a slave-only 1-Wire interface with embedded multidrop controller logic, supporting five ROM function commands (Read ROM, Match ROM, Search ROM, Active-Only Search ROM, Skip ROM) for device singulation and PIO state control. Its internal circuit emulates an open-drain N-MOSFET with no gate drive - switching is purely ROM-matched via bus-level protocol.

Each device responds to initialization (Reset Pulse + Presence Pulse), then executes ROM commands before enabling PIO read/write operations. The PIO pin's logic level is sensed over the same 1-Wire line using read time slots, requiring external pullup; no internal voltage regulator or auxiliary supply is used - all power is harvested parasitically during high bus phases.

Key Specifications

Pinout & Package

DS2405P/T&R is supplied in a 6-pin TSOC surface-mount package (3.7 mm × 4.0 mm × 1.5 mm), optimized for automated assembly and space-constrained MicroLAN nodes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2405P/T&R, DS2413P/T&R offers dual-switch functionality without increasing node count, while DS2406P/T&R trades simplicity for nonvolatile memory - both retain identical ROM-based addressing and parasitic power operation but expand capability beyond basic single-pole switching.

Availability

DS2405P/T&R is available at Aetrix Electronics and suitable for industrial asset tagging, remote load switching, secure access control nodes, and legacy system interface adapters requiring stable component supply and long-term MicroLAN interoperability.

Supply support for DS2405P/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, and computing applications - emphasizing reliability, integration, and low-power operation.

The DS2405P/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 wiring minimization and device uniqueness are critical.

FAQ

What is the primary function of the DS2405P/T&R in a 1-Wire network?

The DS2405P/T&R functions as an addressable open-drain switch - its PIO pin can be individually toggled or sensed over the 1-Wire bus using Match ROM or Search ROM commands. Each DS2405P/T&R contains a unique 64-bit ROM that enables singulation among multiple devices on the same bus, allowing precise control without additional address lines or power supplies.

Does the DS2405P/T&R require an external power supply?

No, the DS2405P/T&R operates entirely on parasitic power harvested from the 1-Wire bus - it stores energy on an internal capacitor during high bus phases and uses that charge to execute ROM commands and drive the PIO pin. No V_CC connection is needed, making DS2405P/T&R ideal for ultra-low-power or batteryless node designs.

How is the PIO pin state read back over the 1-Wire bus?

After issuing a Match ROM or Search ROM command, the bus master sends additional read time slots - the DS2405P/T&R responds with read-0 time slots if PIO is actively pulled low (logic 0), or read-1 time slots if PIO is high-impedance and pulled up externally (logic 1). This allows closed-loop verification of switch state without separate sensing circuitry.

What package type does DS2405P/T&R use, and how many pins are functional?

The DS2405P/T&R uses a 6-pin TSOC surface-mount package. Only three pins are functional: Pin 1 (GND), Pin 2 (DATA), and Pin 3 (PIO). Pins 4 through 6 are No Connect - they are not bonded internally and must remain unconnected in layout.

Can multiple DS2405P/T&R devices share the same 1-Wire bus?

Yes, multiple DS2405P/T&R devices can coexist on a single 1-Wire bus. The built-in multidrop controller and standardized 1-Wire protocol allow the bus master to identify each unit by its unique 64-bit ROM and independently control or monitor their PIO states - enabling scalable MicroLAN deployments with dozens of nodes on one wire.