Analog Devices Inc./Maxim Integrated DS2405

Overview

DS2405 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, and -40°C to +85°C temperature range - used for node-level identification and remote control in distributed sensor networks and access control systems.

For engineers reviewing the DS2405 datasheet, DS2405 pinout, DS2405 application, or DS2405 equivalent, this page delivers verified technical context, exact pin roles, real-world use cases, and validated alternative options for MicroLAN-based switching and identification architectures.

Technical Context

The DS2405 implements a parasitically powered 1-Wire slave interface with embedded multidrop controller logic, enabling ROM-based device singulation via Match ROM (55h), Search ROM (F0h), and Active-Only Search ROM (ECh) commands. Its PIO pin functions as a controllable open-drain output whose state can be both set and read over the same bidirectional bus line.

Communication follows strict 1-Wire timing: reset pulse (≥480μs low), presence pulse (60–240μs), time slots (60–120μs), and data sampling windows (e.g., tRDV = 15μs). The device draws no standby power and relies entirely on charge stored in its internal capacitor during bus high periods.

Key Specifications

Pinout & Package

DS2405 is available in TO-92, SOT-223, and 6-pin TSOC packages. This listing refers to the tape-and-reel version of the base DS2405 (TO-92), with leads 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, DS2413 offers higher drive strength and dual outputs but increases node complexity, while DS2406 adds EEPROM for configuration retention at the cost of larger firmware overhead - DS2405 remains optimal for simple, low-cost, single-output addressable switching where minimal silicon footprint and zero standby power are critical.

Availability

DS2405 is available at Aetrix Electronics and suitable for access control systems, industrial sensor nodes, asset tracking tags, and legacy equipment interfaces requiring stable component supply and long-term MicroLAN compatibility.

Supply support for DS2405 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 precision analog, mixed-signal, and power management ICs for industrial, communications, and computing applications.

The DS2405 belongs to Maxim's 1-Wire addressable switch product line, designed specifically for distributed identification and low-power remote control in MicroLAN architectures - prioritizing parasitic operation, ROM-based security, and minimal wiring.

FAQ

What is the function of the PIO pin on the DS2405?

The PIO pin on the DS2405 is an open-drain N-channel MOSFET output that can be remotely toggled on or off via 1-Wire Match ROM or Search ROM commands. When active, it sinks ≥4mA at 0.4V; when inactive, it presents high impedance and requires an external pullup to report logic high. The DS2405 also allows the bus master to read back the actual logic level of the PIO pin - enabling closed-loop control verification in real time.

Does the DS2405 require an external power supply?

No, the DS2405 operates parasitically - it derives all operating power from the 1-Wire bus by charging an internal capacitor during bus high periods. This eliminates the need for a dedicated V_CC connection, allowing full functionality with only two wires: DATA and GND. The DS2405 remains fully operational across 2.8V to 6.0V bus voltages and draws zero standby current.

How does the DS2405 ensure unique device identification?

The DS2405 contains a factory-lasered 64-bit ROM consisting of an 8-bit family code (05h), a unique 48-bit serial number, and an 8-bit CRC. This ROM is permanently programmed and tested during manufacturing - no two DS2405 devices share the same ID. The bus master uses ROM commands (e.g., Match ROM, Search ROM) to locate and address individual DS2405 units on a shared 1-Wire bus, ensuring absolute node-level identity.

Can multiple DS2405 devices share the same 1-Wire bus?

Yes, multiple DS2405 devices can coexist on a single 1-Wire bus and be individually addressed using their unique 64-bit ROMs. The DS2405 includes embedded multidrop controller logic and supports standard 1-Wire search algorithms (Search ROM, Active-Only Search ROM) to identify and isolate each device. Each DS2405's PIO pin can be independently controlled and read without affecting others on the bus.

What package options are available for the DS2405?

The DS2405 is offered in three package types: TO-92 (through-hole), SOT-223 (4-pin surface mount), and 6-pin TSOC (thin small-outline package). The DS2405/T&R designation refers specifically to the tape-and-reel version of the TO-92 variant, with leads formed to 100 mil (2.54 mm) spacing per mechanical drawing 56-G0006-003 - optimized for automated assembly.