Analog Devices Inc./Maxim Integrated DS2405+

Overview

DS2405+ from Maxim Integrated (now Analog Devices) 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), 2.8V–6.0V operating voltage, -40°C to +85°C temperature range, and >4mA PIO sink capability at 0.4V. It enables remote on/off control and state sensing of individual nodes in multidrop MicroLAN systems for asset tagging and distributed I/O.

For engineers reviewing the DS2405+ datasheet, DS2405+ pinout, DS2405+ application, or DS2405+ equivalent, this page delivers verified electrical specs, TSOC/TO-92/SOT-223 package mapping, 1-Wire ROM command behavior, parasitic power operation, and real-world use cases in industrial node identification and low-power remote switching.

Technical Context

The DS2405+ implements a 1-Wire slave interface with embedded multidrop controller logic, supporting five ROM function commands (Read ROM, Match ROM, Search ROM, Active-Only Search ROM, Skip ROM) to identify and address devices on a shared bus. Its PIO pin operates as a parasitically powered open-drain output with no standby current draw.

Communication follows Dallas Semiconductor's 1-Wire protocol: all data transferred LSB-first, initialization via Reset/Presence Pulse sequence (tRSTL ≥480μs, tPDL 60–240μs), and time-slot-based read/write operations (tSLOT 60–120μs). The device derives full power from the 1-Wire bus using internal capacitor storage, eliminating external V_CC.

Key Specifications

Pinout & Package

DS2405+ is available in TO-92, SOT-223, and 6-pin TSOC surface-mount packages. Pin functions are identical across variants: Pin 1 = Ground, Pin 2 = Data (1-Wire bidirectional), Pin 3 = PIO (open-drain output), Pins 4–6 (TSOC only) = No Connect.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2413+ and DS2406+, the DS2405+ provides the minimal, lowest-cost 1-Wire addressable switch with proven reliability in high-volume industrial tagging - ideal when single-output control, zero standby power, and strict BOM cost targets are primary design constraints.

Availability

DS2405+ is available at Aetrix Electronics and suitable for industrial asset tagging, remote sensor node control, and secure access point switching requiring stable component supply, long-term lifecycle support, and traceable sourcing.

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, designs precision analog, mixed-signal, and digital ICs for industrial, automotive, and communications markets.

The DS2405+ belongs to Maxim's 1-Wire addressable switch product line, engineered specifically for low-power, multidrop identification and control in distributed sensor networks and electronic asset management systems.

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 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 sensed over the same bus. The DS2405+ uses parasitic power, so the PIO pin has no source capability - external pullup is required for logic-high assertion.

Does the DS2405+ require an external power supply?

No, the DS2405+ operates entirely from parasitic power harvested from the 1-Wire bus. During bus high periods, internal capacitance charges; during low periods, that stored energy powers the DS2405+ circuitry. This eliminates the need for V_CC, reducing system wiring and enabling true single-wire operation - a core design feature of the DS2405+.

How does the DS2405+ ensure unique identification on a shared 1-Wire bus?

The DS2405+ 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. This ROM is used in Match ROM and Search ROM commands to isolate and address individual DS2405+ units on a multidrop bus - guaranteeing no two DS2405+ devices share the same identity, a foundational requirement for reliable MicroLAN operation.

What are the supported 1-Wire ROM function commands for the DS2405+?

The DS2405+ supports five ROM function commands: Read ROM (33h), Match ROM (55h), Search ROM (F0h), Active-Only Search ROM (ECh), and Skip ROM (CCh). Match ROM toggles the PIO state; Search ROM discovers all device IDs; Active-Only Search ROM finds only devices with PIO actively low - all are implemented in silicon and fully documented in the DS2405+ datasheet.

Which packages are available for the DS2405+ and how do they differ electrically?

The DS2405+ is offered in TO-92, SOT-223, and 6-pin TSOC packages. All variants share identical pinout (Pin 1=GND, Pin 2=DATA, Pin 3=PIO), electrical specifications, and functional behavior. Differences are purely mechanical: TO-92 is through-hole; SOT-223 and TSOC are surface-mount with distinct footprints and thermal profiles - the DS2405+ itself imposes no electrical distinction between packages.