Analog Devices Inc./Maxim Integrated DS2406+

Overview

DS2406+ from Maxim Integrated (now Analog Devices) is a dual-addressable 1-Wire switch with 1024-bit OTP EPROM, featuring two independently controllable open-drain PIO channels (A and B), factory-lasered 64-bit ROM for absolute device identity, CRC16 error detection, and parasitic or V_CC-powered operation. It enables closed-loop remote control and status monitoring in distributed sensor/actuator nodes.

For engineers reviewing the DS2406+ datasheet, DS2406+ pinout, DS2406+ application, or DS2406+ equivalent, key selection considerations include PIO sink capability (50mA @ 0.4V for channel A, 8mA @ 0.4V for channel B), 1-Wire bus voltage range (2.8V–6.0V), maximum PIO voltage ratings (13V at PIO-A, 6.5V at PIO-B), OTP memory organization (4 × 32-byte pages), and Conditional Search support via user-programmable status register.

Technical Context

The DS2406+ 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 integrates a 64-bit lasered ROM, 1024-bit OTP EPROM, 8-byte status memory (7 bytes EPROM + 1 byte SRAM), and PIO-control logic with channel flip-flops accessible via Status Memory location 7 or Channel Access command.

Memory operations require strict CRC-verified scratchpad loading followed by 12V programming pulses for EPROM writes; reads support both standard Read Memory (F0h) and Extended Read Memory (A5h) with per-page CRC and redirection byte validation. The device supports parasite power but includes V_CC bondout in TSOC package for stable operation during long low-time bus conditions.

Key Specifications

Pinout & Package

DS2406+ is available in TO-92 and lead-free 6-pin TSOC packages. Pin functions differ between packages: TO-92 has 3 pins (GND, DATA, PIO-A); TSOC adds V_CC, NC, and PIO-B for full dual-channel operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2407+, the DS2406+ eliminates Hidden Mode complexity and fixed POR behavior, simplifying integration in deterministic systems; versus DS2413+, it trades off higher PIO drive strength and lower cost for integrated OTP memory and Conditional Search - making DS2406+ optimal for asset-identity-critical, multi-device networks requiring programmable configuration.

Availability

DS2406+ is available at Aetrix Electronics and suitable for industrial sensor nodes, access control panels, asset tracking tags, and smart lighting nodes requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for DS2406+ 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 applications.

The DS2406+ belongs to Maxim's 1-Wire addressable switch family, engineered for distributed control and identification in harsh, space-constrained environments where wiring simplicity and device uniqueness are critical.

FAQ

What is the maximum sink current supported by each PIO channel on the DS2406+?

The DS2406+ PIO-A channel supports up to 50mA sink current at 0.4V, enabling direct drive of moderate-power loads like indicator LEDs or small relays. PIO-B supports 8mA at 0.4V, optimized for logic-level signaling or sensor feedback paths. These values are measured under specified test conditions and define the safe operating limits for sustained DC loading without thermal derating.

Does the DS2406+ require an external power supply, or can it operate parasitically?

The DS2406+ supports both parasitic power (drawing energy from the 1-Wire bus during high periods) and optional V_CC-powered operation. Parasite mode works across the full 2.8V–6.0V 1-Wire voltage range and is sufficient for most applications. The V_CC pin is available only in the 6-pin TSOC package and is recommended when bus low-times exceed typical durations to maintain stable internal state and PIO control.

How does the DS2406+ ensure reliable communication on noisy or long 1-Wire buses?

The DS2406+ incorporates an on-chip CRC16 generator that validates every command, address, and data transfer. The bus master computes and verifies CRCs before and after memory writes, and the device returns per-page CRCs during Extended Read Memory operations. This layered CRC protection detects bit errors caused by EMI, crosstalk, or marginal timing - ensuring robust operation even on 100m+ bus runs with multiple devices.

Can the 1024-bit EPROM in the DS2406+ be reprogrammed multiple times?

No - the DS2406+ uses one-time programmable (OTP) EPROM. Each bit can be changed from '1' to '0' only once during programming; reversal is impossible. Write-protection bits in status memory (addresses 0–3) allow locking entire 32-byte pages after initial programming. This design ensures permanent, tamper-resistant storage of calibration data, serial numbers, or firmware versions without risk of accidental overwrite.

What is the purpose of the Conditional Search feature in the DS2406+?

The Conditional Search feature allows a 1-Wire bus master to discover only DS2406+ devices meeting specific real-time criteria - such as PIO-A or PIO-B output state, static logic level, or voltage transition - without polling all devices. This reduces bus traffic and latency in large networks, enabling efficient event-driven architectures (e.g., identifying only open doors or triggered alarms) while preserving deterministic response time for critical actions.