Analog Devices Inc./Maxim Integrated DS2450S+T&R

Overview

DS2450S+T&R 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), resolution (1–16 bits), and per-channel alarm thresholds. It operates from a single 5V supply or parasitic power, supports multidrop 1-Wire bus topology, and delivers up to 142 kbps in Overdrive mode - used in distributed sensor monitoring systems for industrial voltage supervision and environmental data logging.

For engineers reviewing the DS2450S+T&R datasheet, DS2450S+T&R pinout, DS2450S+T&R application, or DS2450S+T&R equivalent, key selection considerations include 1-Wire bus compatibility, per-channel alarm flagging behavior, SRAM-based configuration retention, VCC vs. parasitic power trade-offs for A/D conversion, and conditional search response timing under threshold violation.

Technical Context

The DS2450S+T&R implements a 4:1 analog multiplexer feeding a successive-approximation ADC core, with each of its four channels (AIN-A through AIN-D) assigned independent control registers for range (2.56V/5.12V), resolution (1–16 bits), and dual alarm thresholds (low/high). Conversion results are stored in a dedicated 8-byte page (Page 0), while Page 1 holds channel-specific control/status bits including output enable (OE), output control (OC), and power-on reset (POR) flag.

It uses Dallas Semiconductor's standard 1-Wire protocol with ROM function commands (e.g., Conditional Search [ECH], Overdrive-Skip ROM [3CH]) and memory-mapped register access via Read Memory [AAH] and Write Memory [55H] commands. CRC-16 protection applies to all memory reads/writes and command sequences, and the device responds to Conditional Search only when AEH/AEL flags are set *and* measured voltage crosses programmed thresholds.

Key Specifications

Pinout & Package

DS2450S+T&R is housed in an 8-pin SOIC (208 mil) surface-mount package with lead-free compliance (+ suffix). Pin functions are electrically isolated per datasheet-defined roles and validated for 1-Wire bus signaling integrity and analog input accuracy.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS2450S+T&R, DS2438Z+ trades voltage input flexibility for integrated current/temperature sensing, while MAX31826+ provides higher thermal accuracy but zero analog voltage monitoring capability - making DS2450S+T&R the only option supporting configurable 4-channel voltage supervision with alarm-driven bus efficiency.

Availability

DS2450S+T&R is available at Aetrix Electronics and suitable for industrial voltage supervision, distributed sensor networks, energy metering subsystems, and automated test fixtures requiring stable component supply and long-term 1-Wire ecosystem compatibility.

Supply support for DS2450S+T&R 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 - emphasizing robustness, integration, and interface simplicity.

The DS2450S+T&R belongs to Maxim's 1-Wire sensor and data-conversion product line, engineered specifically to reduce system-level wiring complexity and microcontroller resource usage in distributed monitoring architectures.

FAQ

What is the function of the NC pin on the DS2450S+T&R?

NC (No Connect) on the DS2450S+T&R is an unconnected internal node with no electrical function. It must remain floating and unattached in PCB layout - soldering or routing to this pin risks compromising device reliability or violating ESD protection design. The DS2450S+T&R datasheet explicitly prohibits connection to NC, and doing so may invalidate parametric performance guarantees for A/D conversion accuracy or 1-Wire signal integrity.

Can the DS2450S+T&R perform conversions without a VCC supply?

Yes, the DS2450S+T&R supports parasitic power operation from the 1-Wire bus alone, but A/D conversion requires a strong 5V pullup applied during the conversion window. Without VCC, the device harvests energy from the DATA line during high periods to sustain logic operation, yet conversion demands higher instantaneous current - hence the external strong pullup. DS2450S+T&R will not complete valid conversions under parasitic power unless this timing-critical pullup is activated within 10 μs of the Convert command CRC completion.

How does the Conditional Search feature work in the DS2450S+T&R?

The DS2450S+T&R responds to Conditional Search [ECH] only when both conditions are met: (1) the AEH (alarm enable high) or AEL (alarm enable low) bit is set in the channel's control register, and (2) the latest A/D result exceeds the corresponding high or low alarm threshold stored in Page 2. This allows the bus master to discover only those DS2450S+T&R devices experiencing out-of-range events - eliminating polling overhead in large multidrop networks where most nodes operate nominally.

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

The DS2450S+T&R's factory-lasered 64-bit ROM contains an 8-bit family code (20h), a unique 48-bit serial number, and an 8-bit CRC - ensuring globally unique identification and enabling deterministic device addressing on shared 1-Wire buses. This ROM allows the bus master to execute Match ROM or Search ROM commands to isolate and communicate with individual DS2450S+T&R units in multidrop configurations without software-assigned addresses or manual configuration.

Does the DS2450S+T&R support Overdrive mode, and how is it enabled?

Yes, the DS2450S+T&R supports Overdrive mode at 142 kbps. It is enabled by issuing the Overdrive-Skip ROM [3CH] command (for single-drop buses) or Overdrive-Match ROM (for multidrop), which sets the OD flag internally. All subsequent communication occurs at Overdrive speed until a reset pulse ≥480 μs is issued. DS2450S+T&R validates Overdrive timing margins per Figure 9 of its datasheet, and improper pullup resistor value (<2.2kΩ) will cause communication failure in this mode.