Analog Devices Inc./Maxim Integrated DS2406X

Overview

DS2406X from Maxim Integrated (now Analog Devices) is a dual-channel addressable 1-Wire switch with 1024-bit OTP EPROM, designed for remote open-drain transistor control and status monitoring in distributed sensor/actuator nodes. It features two independently controllable PIO channels (A: 50mA sink @ 0.4V; B: 8mA sink @ 0.4V), operates from 2.8V–6.0V on the 1-Wire bus, and integrates a factory-lasered 64-bit ROM for guaranteed device uniqueness - used in industrial asset tagging and HVAC zone control.

For engineers reviewing the DS2406X datasheet, DS2406X pinout, DS2406X application, or DS2406X equivalent, this page delivers verified technical context, exact pin roles for TO-92 and TSOC packages, real-world closed-loop control use cases, and validated alternative parts with documented functional differences - all grounded in Maxim's official DS2406 datasheet (Rev. 033109).

Technical Context

The DS2406X implements a hierarchical 1-Wire protocol stack: ROM function commands (e.g., Conditional Search, Match ROM) must precede memory or PIO-control commands. Its internal architecture includes a 64-bit lasered ROM (family code 12h), 1024-bit OTP EPROM (4 × 32-byte pages), 8-byte status memory (7 bytes EPROM + 1 byte SRAM), and CRC16 generator for error detection on all data transfers.

PIO control is managed via status memory bitfields (e.g., bits 5–6 of address 7 control channel flip-flops) and Channel Access command (F5h); conditional search uses user-programmable settings stored at status memory address 7. Programming requires 12V pulses applied to the 1-Wire line, with strict timing (480 µs pulse width) and bus isolation during EPROM write cycles.

Key Specifications

Pinout & Package

DS2406X is available in two lead-free packages: TO-92 (3-pin) and 6-pin TSOC. The TO-92 variant lacks Vcc and NC pins; the TSOC variant adds Vcc (pin 4) for optional external power and NC (pin 5), enabling stable operation during long 1-Wire low periods or disconnection events.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2407P+, DS2406X removes Hidden Mode complexity and fixed power-on defaults - simplifying firmware integration and reducing qualification time. Against DS2413+, DS2406X trades raw noise immunity for integrated 1024-bit EPROM - making it uniquely suited for traceable, self-describing nodes in asset-intensive deployments.

Availability

DS2406X is available at Aetrix Electronics and suitable for industrial asset tagging, HVAC zone control, energy-harvested sensor nodes, and access control perimeter systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for DS2406X 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 (acquired by Analog Devices in 2021) designs precision analog, mixed-signal, and digital ICs for industrial, automotive, and communications markets - emphasizing reliability, integration, and low-power operation.

The DS2406X belongs to Maxim's 1-Wire® interface product line, engineered specifically for distributed identification, control, and data logging in resource-constrained embedded systems where wiring simplicity and device uniqueness are critical.

FAQ

What is the maximum sink current supported by each PIO channel on the DS2406X?

The DS2406X PIO-A channel supports up to 50mA sink current at 0.4V, enabling direct drive of small relays or indicator LEDs. PIO-B supports 8mA at 0.4V, optimized for logic-level signaling or low-power status indicators. These values are measured under specified thermal conditions and define the absolute DC load limits for safe operation of DS2406X in closed-loop control applications.

Does the DS2406X require an external power supply, or can it operate using parasitic power only?

The DS2406X supports parasitic power operation from the 1-Wire bus - storing charge on an internal capacitor during high bus periods to sustain operation during low periods. However, for applications involving long bus low times or intermittent disconnection, the TSOC package's Vcc pin (pin 4) must be connected to an external 2.8V–6.0V supply to maintain status integrity. The TO-92 variant lacks Vcc and relies solely on parasitic power.

How does the DS2406X ensure unique device identification on a shared 1-Wire bus?

The DS2406X incorporates a factory-lasered 64-bit ROM containing an 8-bit family code (12h), a unique 48-bit serial number, and an 8-bit CRC - guaranteeing absolute identity across all units. This ROM is read-only and tested at wafer level, eliminating duplicates and enabling unambiguous device selection via Match ROM or Search ROM commands without manual configuration - a core requirement for scalable DS2406X deployments.

Can the 1024-bit EPROM memory in the DS2406X be reprogrammed multiple times?

No - the DS2406X uses one-time programmable (OTP) EPROM. Each bit can transition only from 1 to 0 during programming; reversal is physically impossible. Write protection is implemented per 32-byte page via status memory bits 0–3. Once a page is write-protected, it remains read-only for the lifetime of the DS2406X. Data updates require page redirection using status memory addresses 1–4, not reprogramming.

What is the purpose of the Conditional Search feature in the DS2406X, and how is it configured?

The Conditional Search feature allows a 1-Wire bus master to selectively address DS2406X devices based on real-time conditions - such as PIO-A/B output state, static logic level, or voltage transition - rather than polling all devices. Configuration is done by writing user-defined condition codes to status memory address 7. This reduces bus traffic and latency in networks with dozens of DS2406X units, directly improving system responsiveness and power efficiency.