Analog Devices Inc./Maxim Integrated DS1631AU+T&R

Overview

DS1631AU+T&R from Maxim Integrated is a high-precision digital thermometer and thermostat IC with ±0.5°C accuracy from 0°C to +70°C, 9–12-bit user-selectable resolution (0.0625°C to 0.5°C step), and -55°C to +125°C operating range. It features nonvolatile TH/TL trip-point registers, push-pull TOUT output, and 2-wire (I²C-compatible) interface - used in thermal monitoring of network routers, cellular base stations, and portable electronics.

For engineers reviewing the DS1631AU+T&R datasheet, DS1631AU+T&R pinout, DS1631AU+T&R application, or DS1631AU+T&R equivalent, this page delivers verified technical context, validated pin functions, confirmed I²C timing compliance (400kHz max), NV EEPROM retention (10 years), and real-world thermostat hysteresis implementation guidance - all specific to the DS1631AU+T&R variant in µSOP-8 packaging.

Technical Context

The DS1631AU+T&R implements a bandgap-based temperature sensor paired with a delta-sigma ADC to deliver calibrated digital temperature data over I²C. Its configuration register controls resolution (R0/R1 bits), TOUT polarity (POL), and conversion mode (1SHOT bit), with POL and 1SHOT stored in NV EEPROM for power-up persistence.

Thermostat operation relies on real-time comparison between measured temperature and user-programmed TH/TL registers (also NV EEPROM). TOUT updates after each conversion and supports active-high or active-low logic via POL; hysteresis is fully defined by the gap between TH and TL values - no internal fixed hysteresis is applied.

Key Specifications

Pinout & Package

DS1631AU+T&R is housed in an 8-pin µSOP package (3.0mm × 3.0mm, 0.5mm pitch), optimized for high-density thermal sensing nodes. Pin functions are validated per Maxim's official datasheet Figure 1 and Table 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1631AU+T&R, DS1621U+T&R lacks nonvolatile trip-point memory and narrower accuracy range, while MAX31820MUA+ replaces I²C with 1-Wire and removes hardware TOUT - making DS1631AU+T&R the only option supporting true autonomous, field-programmable thermostat operation in µSOP-8.

Availability

DS1631AU+T&R is available at Aetrix Electronics and suitable for network infrastructure, cellular base station thermal management, and portable electronics requiring stable component supply with guaranteed long-term availability.

Supply support for DS1631AU+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 and mixed-signal ICs for demanding industrial, communications, and computing applications.

The DS1631AU+T&R belongs to Maxim's high-accuracy digital thermometer family, engineered specifically for autonomous thermal monitoring and hardware-based thermostat control in space- and power-constrained systems.

FAQ

What is the key functional difference between DS1631AU+T&R and DS1631U+T&R?

The DS1631AU+T&R automatically begins temperature conversions at power-up in continuous mode (1SHOT=0 default), enabling true standalone thermostat operation. In contrast, DS1631U+T&R remains in low-power idle until commanded via I²C Start Convert T. Both share identical accuracy (±0.5°C), resolution, and µSOP-8 packaging - but only DS1631AU+T&R supports autonomous thermal response without host intervention.

Does DS1631AU+T&R require external components to operate as a thermostat?

No. DS1631AU+T&R requires only VDD, GND, and pullup resistors on SDA/SCL for I²C communication. Its push-pull TOUT pin drives loads directly (e.g., MOSFET gate or logic input), and TH/TL trip points are stored in NV EEPROM - so once programmed, DS1631AU+T&R functions as a self-contained thermostat with no external comparators, resistors, or microcontroller needed.

How is hysteresis implemented in DS1631AU+T&R?

Hysteresis in DS1631AU+T&R is fully user-defined via independent TH (upper) and TL (lower) trip-point registers stored in EEPROM. When temperature ≥ TH, TOUT asserts; it remains asserted until temperature falls below TL. The difference (TH – TL) sets hysteresis magnitude - e.g., TH = +75°C and TL = +65°C yields 10°C hysteresis. No fixed internal hysteresis is applied.

Can DS1631AU+T&R be used on a standard I²C bus with other devices?

Yes. DS1631AU+T&R uses standard I²C protocol (400kHz max) and a 7-bit slave address (1001A2A1A0), allowing up to eight units on one bus. It complies with I²C electrical specs: open-drain SDA, CMOS SCL, and ACK/NACK timing - and coexists with standard I²C peripherals like EEPROMs, RTCs, and GPIO expanders without bus contention.

What is the EEPROM endurance and data retention for TH/TL registers in DS1631AU+T&R?

The TH and TL registers in DS1631AU+T&R are stored in EEPROM rated for 50,000 write cycles and 10 years of data retention at -55°C to +55°C. This specification is validated per Maxim's official datasheet (page 3, EEPROM AC Electrical Characteristics), ensuring field-programmed trip points remain reliable across industrial product lifecycles.