Analog Devices Inc./Maxim Integrated DS75S+T&R

Overview

The DS75S+T&R from Maxim Integrated is a digital thermometer and thermostat IC with 9–12-bit user-configurable resolution, ±2°C accuracy from –25°C to +100°C, and –55°C to +125°C operating range. It communicates via 2-wire I²C-compatible interface, features open-drain O.S. thermostat output, and supports up to eight devices on one bus using A0–A2 address pins. Used in thermal monitoring of PCs, base stations, and office equipment.

For engineers reviewing the DS75S+T&R datasheet, DS75S+T&R pinout, DS75S+T&R application, or DS75S+T&R equivalent, key selection criteria include I²C compatibility with LM75, programmable fault tolerance (1/2/4/6 consecutive out-of-limit readings), comparator/interrupt thermostat modes, shutdown current of 1µA, and lead-free 8-pin SO package with tape-and-reel packaging (2500 pcs).

Technical Context

The DS75S+T&R implements a bandgap-based temperature sensor with delta-sigma ADC, delivering calibrated 16-bit two's complement temperature data. Its configuration register controls resolution (R1/R0), thermostat mode (TM), polarity (POL), fault tolerance (F1/F0), and shutdown (SD), all volatile and power-up defaulting to 9-bit, comparator mode, active-low O.S., FT=1, and active operation.

Thermostat logic compares real-time temperature against user-programmed TOS and THYST registers using resolution-matched MSBs; O.S. activation follows configurable fault tolerance and persists or auto-clears depending on selected mode (comparator vs. interrupt). The 2-wire interface uses standard I²C timing with 400kHz max SCL frequency and requires external pull-ups on SDA/SCL.

Key Specifications

Pinout & Package

DS75S+T&R is supplied in a lead-free, 150mil 8-pin SOIC package (SO-8), optimized for automated assembly and reflow compatibility.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital thermometer and thermostat applications.

Compared with LM75BIMX-3/NOPB, DS75S+T&R adds resolution scaling, fault tolerance, and dual thermostat modes-enabling adaptive thermal response. Against STTS751DTYQTR, DS75S+T&R trades EEPROM persistence for hardware addressability and broader voltage tolerance, better fitting multi-sensor, cost-sensitive industrial designs.

Availability

DS75S+T&R is available at Aetrix Electronics and suitable for PC thermal management, cellular infrastructure monitoring, and office equipment safety systems requiring stable component supply and long-term manufacturability.

Supply support for DS75S+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, communications, computing, and consumer applications.

The DS75S+T&R belongs to Maxim's digital temperature sensor product line, engineered for embedded thermal monitoring where I²C simplicity, configurability, and robustness across extended temperature ranges are essential.

FAQ

What is the default resolution and thermostat mode of the DS75S+T&R at power-up?

The DS75S+T&R powers up with 9-bit resolution and thermostat configured in comparator mode, active-low O.S. polarity, TOS = 80°C, THYST = 75°C, and fault tolerance = 1. These defaults ensure immediate functionality without configuration-making DS75S+T&R usable as a standalone thermostat in simple applications. All settings are volatile and reset on power cycle.

Does the DS75S+T&R require external components for basic temperature measurement?

No, the DS75S+T&R requires no external components for temperature sensing-it integrates a bandgap sensor, delta-sigma ADC, and digital processing core. Only external pull-up resistors on SDA and SCL lines are needed for I²C operation, and a bypass capacitor on VDD is recommended. This eliminates calibration, compensation, or signal-conditioning circuitry typically needed with discrete sensors.

How does the fault tolerance setting affect thermostat behavior in the DS75S+T&R?

The DS75S+T&R fault tolerance (set by F1/F0 bits) defines how many consecutive out-of-limit temperature readings must occur before O.S. activates-values are 1, 2, 4, or 6 conversions. This prevents false triggers from transient thermal noise. In comparator mode, O.S. remains active until temperature falls below THYST; in interrupt mode, O.S. clears only upon register read or shutdown, enabling precise event sequencing.

Can the DS75S+T&R operate on a 3.3V supply, and what is its current draw in active mode?

Yes, the DS75S+T&R operates across +2.7V to +5.5V, fully supporting 3.3V systems. In active mode performing temperature conversions, it draws 1000µA (typical); during I²C communication only (no conversion), current drops to 100µA. In shutdown mode, supply current is reduced to 1µA-ideal for low-power wake-on-temperature applications.

Is the DS75S+T&R pin-compatible with the LM75, and what does that mean for legacy designs?

Yes, the DS75S+T&R is pin- and software-compatible with the LM75-same SO-8 footprint, identical pin functions (SDA, SCL, O.S., GND, A0–A2, VDD), and matching I²C register map and command protocol. This allows direct replacement in existing LM75-based layouts without PCB changes, while adding enhanced features like resolution scaling, fault tolerance, and interrupt-mode thermostat operation.