Analog Devices Inc./Maxim Integrated DS2450S+

Overview

DS2450S+ from Maxim Integrated is a 1-Wire quad analog-to-digital converter with four high-impedance voltage inputs, 16-bit successive-approximation architecture, user-programmable input ranges (2.56V or 5.12V), 1–16-bit resolution per channel, and integrated alarm threshold detection. It operates from a single 5V supply or parasitic power, supports multidrop 1-Wire bus topology, and targets distributed sensor monitoring in industrial control and environmental sensing systems.

For engineers reviewing the DS2450S+ datasheet, DS2450S+ pinout, DS2450S+ application, or DS2450S+ equivalent, key selection considerations include its 1-Wire interface compatibility, per-channel programmable resolution and alarm thresholds, VCC/parasitic power flexibility, 8-pin SOIC package constraints, and conditional search capability for event-driven system wake-up.

Technical Context

The DS2450S+ implements a successive-approximation ADC with a 4:1 analog multiplexer and independent SRAM-based control registers per channel. Each channel supports configurable input range (2.56V/5.12V), resolution (1–16 bits), and dual alarm thresholds (high/low), with automatic flag generation upon violation.

It uses the Dallas Semiconductor 1-Wire protocol with standard (16.3 kbps) or overdrive (142 kbps) communication modes, requires no external clock, and integrates a 16-bit CRC generator for memory read/write integrity. Power delivery is flexible: VCC-supplied (enabling concurrent bus activity during conversion) or parasitic (requiring strong 5V pullup during A/D conversion).

Key Specifications

Pinout & Package

DS2450S+ is housed in an 8-pin SOIC (208 mil) surface-mount package with exposed pad not electrically connected. Pin functions are fixed and non-multiplexed; NC pin must remain unconnected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 1-Wire analog monitoring applications.

Compared with DS2450S+, DS2438Z+ adds integrated temperature/current sensing but sacrifices per-channel voltage range programming and alarm granularity, while MAX31826+ provides superior thermal accuracy but zero analog input functionality - making DS2450S+ uniquely suited for flexible, multi-voltage monitoring in constrained wiring environments.

Availability

DS2450S+ is available at Aetrix Electronics and suitable for industrial sensor nodes, environmental monitoring systems, smart building HVAC control, and legacy equipment retrofit kits requiring stable component supply and long-term 1-Wire ecosystem compatibility.

Supply support for DS2450S+ 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 applications.

The DS2450S+ belongs to Maxim's 1-Wire sensor interface product line, engineered specifically to simplify distributed analog sensing over minimal-conductor wiring while maintaining device-level traceability and event-driven responsiveness.

FAQ

What is the function of the NC pin on the DS2450S+?

The NC (No Connect) pin on the DS2450S+ has no internal connection and must remain unconnected in the PCB layout. It is not tied to ground, VCC, or any internal circuitry - leaving it floating ensures correct device operation and avoids unintended biasing or leakage paths that could affect analog measurement accuracy or 1-Wire signaling integrity on the DS2450S+.

Can the DS2450S+ perform A/D conversions while powered only by the 1-Wire bus?

Yes, the DS2450S+ supports parasitic power operation, but A/D conversions require additional energy beyond what the 1-Wire bus can supply during normal signaling. When operating parasitically, the bus master must activate a strong 5V pullup on the DATA line for the duration of each conversion - otherwise the DS2450S+ will not complete accurate measurements due to insufficient supply voltage and current during sampling.

How does the DS2450S+ handle alarm conditions across multiple devices on a shared 1-Wire bus?

The DS2450S+ uses hardware-accelerated Conditional Search: when any enabled channel's measured voltage crosses its programmed high or low threshold, the DS2450S+ autonomously responds to a Conditional Search ROM command without host polling. This allows the bus master to rapidly identify only those DS2450S+ units requiring attention - reducing bus traffic and latency versus scanning all devices individually.

What is the significance of the 64-bit ROM in the DS2450S+?

The DS2450S+ features a factory-lasered 64-bit ROM containing an 8-bit family code (0x20), a unique 48-bit serial number, and an 8-bit CRC. This ROM provides absolute device identity, enables reliable multidrop addressing via Match ROM or Search ROM commands, and ensures protocol compliance - the family code tells the bus master that the DS2450S+ requires specific 1-Wire timing and command sequences.

Does the DS2450S+ support simultaneous conversion across all four channels?

No, the DS2450S+ performs sequential A/D conversions - one channel after another in fixed order (A → B → C → D) - even when multiple channels are selected in the input mask. Total conversion time scales linearly with the number of enabled channels and selected bit resolution (e.g., 4 × 12-bit conversions take ≤ 4 ms). There is no hardware support for true parallel sampling or simultaneous result capture on the DS2450S+.