Texas Instruments TMP451AIDQFR

Overview

TMP451AIDQFR from Texas Instruments is a high-accuracy ±1°C remote and local digital temperature sensor IC with SMBus interface, 0.0625°C resolution, series-resistance cancellation, and η-factor/offset correction - used for thermal monitoring of processors, FPGAs, and ASICs in servers, telecom equipment, and embedded systems.

For engineers reviewing the TMP451AIDQFR datasheet, TMP451AIDQFR pinout, TMP451AIDQFR application, or TMP451AIDQFR equivalent, key selection considerations include its dual-channel (local + remote diode) measurement capability, 1.7 V to 3.6 V supply range, 27 µA operating current, 8-pin WSON package, and programmable digital filter for noise immunity in high-speed digital environments.

Technical Context

The TMP451AIDQFR integrates a local thermal sensor and a remote junction sensor interface supporting NPN/PNP transistors or substrate diodes. It implements series-resistance cancellation up to 1 kΩ and programmable η-factor (1.008 typical) to correct nonideal diode behavior. Its SMBus-compatible two-wire interface supports fast mode (400 kHz) and high-speed mode (2.5 MHz).

It features dual open-drain outputs - THERM (pin 4) and ALERT/THERM2 (pin 6) - each configurable for overtemperature alerting with user-defined hysteresis and consecutive violation thresholds. Conversion timing is fixed at 34 ms (one-shot, local + remote), and internal registers support extended temperature range (–64°C to 191°C) via RANGE bit configuration.

Key Specifications

Pinout & Package

Package: 8-pin WSON (DQF), 2.00 mm × 2.00 mm, exposed thermal pad, moisture sensitivity level 2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar remote/local temperature sensing applications.

Compared with LM95235CIMMX/NOPB and MAX6642AESA+, the TMP451AIDQFR delivers superior accuracy, robust noise rejection via dual analog/digital filtering, and production-ready calibration flexibility - critical for high-density compute and 5G infrastructure thermal management.

Availability

TMP451AIDQFR is available at Aetrix Electronics and suitable for server thermal management, telecom base station cooling, and FPGA/ASIC junction monitoring requiring stable component supply across multi-year production cycles.

Supply support for TMP451AIDQFR 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

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, precision, and energy efficiency.

The TMP451AIDQFR belongs to TI's precision analog temperature sensor product line, designed specifically for high-accuracy, low-power thermal monitoring in computing, communications, and industrial systems where junction-level insight prevents system failure.

FAQ

What is the maximum remote sensor series resistance the TMP451AIDQFR can cancel?

The TMP451AIDQFR supports automatic series resistance cancellation up to 1 kΩ on the D+ and D− lines. This feature compensates for PCB trace resistance and optional external RC filters, eliminating the need for manual offset calibration. The cancellation is active by default and applies to both local and remote temperature measurements in the TMP451AIDQFR device.

Does the TMP451AIDQFR support extended temperature range operation beyond –40°C to 125°C?

Yes, the TMP451AIDQFR supports an extended reporting range of –64°C to 191°C when the RANGE bit (bit 2) in the configuration register is set. This uses extended binary encoding with a 64-count offset. However, the device is only specified for ambient operation from –40°C to 125°C, and remote diodes are typically rated –55°C to 150°C - so actual usable range depends on sensor and application constraints.

How does the programmable digital filter in the TMP451AIDQFR improve thermal measurement reliability?

The TMP451AIDQFR's programmable digital filter performs a moving average of either four (Level 1) or eight (Level 2) consecutive remote temperature samples before storing the result. This reduces susceptibility to transient noise from nearby high-speed digital signals. The filtered value is used for both ALERT and THERM limit comparisons, preventing false thermal interrupts in electrically noisy environments like CPU or FPGA motherboards.

Can the ALERT/THERM2 pin on the TMP451AIDQFR be used independently of the THERM pin?

Yes - the ALERT/THERM2 pin (pin 6) is software-configurable as either a second independent THERM output or an SMBus alert signal. When configured as THERM2, it uses the same limit registers and hysteresis settings as THERM (pin 4) but can be asserted based on different channels (e.g., THERM for local, THERM2 for remote). Configuration is done via the CONFIG register bits in the TMP451AIDQFR.

What is the SMBus timing compliance of the TMP451AIDQFR?

The TMP451AIDQFR supports SMBus Fast Mode (up to 400 kHz) and High-Speed Mode (up to 2.5 MHz). It meets SMBus timing requirements including t(HDSTA), t(SUDAT), and t(BUF), with built-in spike suppression filters and Schmitt-trigger inputs on SDA/SCL. The device also implements SMBus time-out (20–30 ms) to recover from bus lockups - a key reliability feature not found in basic I²C sensors like the TMP451AIDQFR's predecessors.