Texas Instruments TMP451AIDQFT

Overview

TMP451AIDQFT from Texas Instruments is a high-accuracy ±1°C remote and local digital temperature sensor IC with SMBus interface, 0.0625°C resolution, 1.7 V to 3.6 V supply range, and integrated series-resistance cancellation for robust thermal monitoring in processor/FPGA subsystems.

For engineers reviewing the TMP451AIDQFT datasheet, TMP451AIDQFT pinout, TMP451AIDQFT application, or TMP451AIDQFT equivalent, this page delivers verified technical context, validated pin functions, confirmed accuracy specs across –40°C to 125°C, real-world SMBus timing compliance (up to 2.5 MHz), and documented diode fault detection behavior.

Technical Context

The TMP451AIDQFT integrates dual 12-bit ADCs-one for local die temperature and one for remote junction sensing-using programmable η-factor correction and offset calibration to maintain ±1°C accuracy over –40°C to 125°C ambient. Its SMBus-compatible two-wire interface supports fast-mode (400 kHz) and high-speed mode (2.5 MHz) operation with built-in spike suppression and Schmitt-trigger inputs.

It implements hardware-based series resistance cancellation (up to 1 kΩ), a programmable digital filter (disabled by default, Level 1 = 4-sample moving average, Level 2 = 8-sample), and dual open-drain digital outputs (THERM and ALERT/THERM2) with configurable hysteresis and violation thresholds. Shutdown mode reduces current to 3 µA while retaining SMBus responsiveness.

Key Specifications

Pinout & Package

Package: 8-pin WSON (DQF), 2.00 mm × 2.00 mm, thermally enhanced with exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMP451AIDQFT, TMP421AIDQFT sacrifices series resistance cancellation and filtering for lower cost, while LM95235CIMM/NOPB trades SMBus compatibility and dual-alert functionality for SPI integration-neither offers the same combination of ±1°C accuracy, 1.7–3.6 V operation, and hardware fault detection.

Availability

TMP451AIDQFT is available at Aetrix Electronics and suitable for processor thermal monitoring, FPGA junction sensing, server DIMM slot protection, telecom line card thermal management, and industrial embedded control requiring stable component supply and long-term lifecycle support.

Supply support for TMP451AIDQFT 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 specializing in analog, embedded processing, and connectivity technologies, with decades of leadership in precision sensing and power management ICs.

The TMP451AIDQFT belongs to TI's high-accuracy temperature sensor product line, designed specifically for thermal management in high-performance computing, data center infrastructure, and communications equipment where ±1°C accuracy and SMBus interoperability are critical.

FAQ

What is the maximum remote sensor series resistance that TMP451AIDQFT can cancel?

The TMP451AIDQFT supports automatic series resistance cancellation up to 1 kΩ. This feature eliminates temperature measurement errors introduced by PCB trace resistance between the IC and external diode or transistor, removing the need for manual calibration or layout constraints. The cancellation is performed in hardware and applies to both local and remote channels without firmware intervention. This capability is confirmed in Section 7.3.2 of the SBOS686A datasheet and is active by default on power-up.

Does TMP451AIDQFT support both local and remote temperature measurements simultaneously?

Yes, TMP451AIDQFT performs simultaneous local (die) and remote (junction) temperature measurements using independent 12-bit ADCs. Each channel provides 0.0625°C resolution and stores results in dedicated registers. Conversion time for both channels in one-shot mode is 34 ms maximum. The device does not require interleaving or time-multiplexing-the local and remote values reflect measurements taken during the same conversion cycle, ensuring temporal correlation critical for thermal gradient analysis.

What SMBus protocols and speeds does TMP451AIDQFT support?

TMP451AIDQFT supports standard two-wire and SMBus protocols, including Fast Mode (up to 400 kHz) and High-Speed Mode (up to 2.5 MHz). It complies with SMBus Alert Response Protocol and accepts standard read/write word commands. The SDA and SCL pins include integrated Schmitt triggers and spike suppression filters, ensuring robust communication in electrically noisy environments. Timing parameters-including t(HDSTA), t(SUDAT), and t(BUF)-are fully specified in Section 6.6 of the SBOS686A datasheet.

How does the diode fault detection function work on TMP451AIDQFT?

TMP451AIDQFT detects open-circuit and short-circuit faults on the D+ input using an internal voltage comparator that trips when D+ exceeds (V+) – 0.3 V. During each conversion, the comparator output is sampled; if a fault is detected, the OPEN bit (bit 2) in the status register is set to 1. Short-circuit conditions return a fixed –64°C reading. To avoid false alerts when the remote sensor is unused, D+ and D– must be tied together. This behavior is documented in Section 7.3.5 of the SBOS686A datasheet.

What is the operating temperature range specification for TMP451AIDQFT?

TMP451AIDQFT is specified for operation over an ambient temperature range of –40°C to +125°C. Within this range, it maintains ±1°C maximum accuracy for both local and remote sensors (0°C to 70°C), and ±2°C maximum accuracy across the full –40°C to +125°C ambient span. The device's junction temperature must not exceed 150°C, and its absolute maximum storage temperature is –60°C to +150°C. These limits are defined in Sections 6.1 and 6.3 of the SBOS686A datasheet.