Analog Devices Inc./Maxim Integrated DS2406

Overview

DS2406 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 pins (A and B), 64-bit unique ROM identity, CRC16 error detection, and operates parasitically from a single 1-Wire bus (2.8–6.0V) or with optional Vcc supply (TSOC only). Used in industrial asset tagging, environmental monitoring nodes, and secure device identification systems.

For engineers reviewing the DS2406 datasheet, DS2406 pinout, DS2406 application, or DS2406 equivalent, key selection criteria include its dual-PIN open-drain sink capability (50mA @ 0.4V for PIO-A, 8mA @ 0.4V for PIO-B), 13V/6.5V max PIO voltage ratings, 1-Wire conditional search support, 1024-bit user-programmable EPROM organized in four 32-byte pages, and factory-lasered 64-bit ROM with 8-bit family code (12h).

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 functions. 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 mapped to Status Memory location 7.

Memory operations use an 8-bit scratchpad buffer with CRC16 verification before programming; EPROM writes require a 12V programming pulse applied to the 1-Wire bus. The device supports parasite power operation but includes a Vcc bondout (TSOC only) for stable operation during long low-time bus conditions or disconnection events.

Key Specifications

Pinout & Package

DS2406 is available in TO-92 (3-pin) and 6-pin TSOC packages. TO-92 uses pins 1 (GND), 2 (DATA), 3 (PIO-A); TSOC adds Vcc (pin 4), NC (pin 5), and PIO-B (pin 6). Vcc bondout and PIO-B are exclusive to TSOC package.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2407, DS2406 removes Hidden Mode and power-on defaults - simplifying integration and reducing configuration risk. Against DS2413, DS2406 trades EEPROM flexibility for OTP permanence, CRC-secured conditional search, and higher PIO-A drive strength - making it optimal for tamper-resistant identification and industrial control.

Availability

DS2406 is available at Aetrix Electronics and suitable for industrial asset tagging, environmental sensor node control, secure access control panels, and legacy equipment retrofit interfaces requiring stable component supply and long-term obsolescence support.

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, communications, and computing markets.

The DS2406 belongs to Maxim's 1-Wire® interface product line, engineered specifically for low-pin-count, multi-drop, battery-efficient identification and control in distributed sensing and automation systems.

FAQ

What is the primary function of the DS2406 in a 1-Wire network?

The DS2406 serves as a dual-channel addressable switch with integrated 1024-bit OTP EPROM and unique 64-bit ROM identity. It enables remote control and status monitoring of two open-drain outputs (PIO-A and PIO-B) over a single 1-Wire bus, eliminating the need for separate address, data, and control lines. Its design allows multiple DS2406 units to coexist on one bus, each responding individually to commands - making DS2406 ideal for distributed sensor/actuator nodes where space, wiring, and power are constrained.

Can the DS2406 operate without an external power supply?

Yes, the DS2406 supports parasite power operation - deriving all operating energy from the 1-Wire bus via internal capacitor charging during high bus states. This enables true single-wire connectivity in battery-free or low-power installations. However, when bus low-times exceed safe limits (e.g., long cables, high node count), or during EPROM programming (which requires 12V pulses), connecting Vcc (TSOC package only) ensures stable operation. The DS2406 automatically detects Vcc presence via Status Memory location 7, bit 7 - a feature critical for fail-safe behavior in mission-critical DS2406 deployments.

How does the DS2406 ensure data integrity during memory writes?

The DS2406 enforces data integrity through a two-stage hardware CRC16 verification process. First, after transmitting a command, address, and data byte, the bus master reads back a 16-bit CRC computed by the DS2406 - confirming correct reception. Only upon CRC match does the master apply the 12V programming pulse. Second, after programming, the master reads the target EPROM byte to verify bit-wise AND consistency. This dual-check mechanism prevents silent corruption and is mandatory for reliable DS2406 field operation - especially in environments with electrical noise or marginal bus timing.

What distinguishes the DS2406 from the DS2407 beyond compatibility?

While DS2406 is fully compatible with DS2407 at the pin and protocol level, it omits two DS2407-specific features: user-programmable power-on settings and Hidden Mode. DS2406 defaults to fixed power-on behavior (PIOs off) and always responds to Read ROM - simplifying initialization and debugging. Additionally, DS2406's Status Memory location 6 is factory-set to 00h to distinguish it from DS2407, which uses that byte to enter Hidden Mode. These omissions make DS2406 more predictable and easier to integrate in deterministic control systems where DS2406's streamlined functionality suffices.

Is the 1024-bit EPROM in the DS2406 truly one-time programmable?

Yes, the DS2406's 1024-bit EPROM is strictly one-time programmable (OTP): bits can only transition from 1 to 0 during programming, never from 0 to 1. Once written, data cannot be erased or rewritten - ensuring permanent, tamper-resistant storage of calibration data, asset IDs, or firmware signatures. Page-level write protection (via Status Memory bits 0–3) further locks entire 32-byte pages after initial programming. This OTP architecture makes DS2406 suitable for applications where data immutability is required - unlike EEPROM-based alternatives such as DS2413, where DS2406's permanence delivers stronger assurance of data authenticity.