Texas Instruments TMP6431DYAT

Overview

TMP6431DYAT from Texas Instruments is a silicon-based linear positive temperature coefficient (PTC) thermistor in SOT-5X3 (DYA) package, delivering 47-kΩ nominal resistance at 25 °C with ±1% tolerance over 0 °C to 70 °C, 6400 ppm/°C TCR at 25 °C, and operation from –40 °C to +150 °C - used for high-accuracy thermal threshold detection in motor control and chargers.

For engineers reviewing the TMP6431DYAT datasheet, TMP6431DYAT pinout, TMP6431DYAT application, or TMP6431DYAT equivalent, key selection considerations include its linear R–T behavior eliminating NTC linearization circuitry, built-in fail-safe response during short-circuit events, low self-heating due to 100 µA max bias current, and compatibility with ratiometric ADC voltage-divider designs using 47-kΩ bias resistors.

Technical Context

The TMP6431DYAT operates as a two-terminal passive PTC sensor whose resistance increases linearly with temperature across –40 °C to +150 °C. Its silicon process enables consistent 6400 ppm/°C TCR at 25 °C and <0.2% TCR tolerance over full range, enabling direct polynomial or LUT-based temperature conversion without external linearization.

It requires positive biasing (pin 2 at higher potential than pin 1) and supports both voltage-divider (with 47-kΩ top resistor) and precision current-source biasing. Thermal response time is 0.6 s in stirred liquid and 3.2 s in still air, with self-heating minimized by ≤100 µA operating current and low thermal mass.

Key Specifications

Pinout & Package

The TMP6431DYAT is housed in a 2-pin SOT-5X3 (DYA) package measuring 0.60 mm × 1.00 mm, optimized for 0603 footprint compatibility and high-density PCB layouts near heat sources.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear PTC thermistor applications.

Compared with TMP6431DYAT, TMP6411DYAT offers lower R25 for reduced bias power in low-voltage systems but requires redesign of bias network, while TMP6431DEC provides identical performance in a smaller footprint with lower max ambient rating - making TMP6431DYAT the optimal choice for high-temp, 5-V ratiometric applications requiring long-term stability at 150 °C.

Availability

TMP6431DYAT is available at Aetrix Electronics and suitable for motor control thermal protection, USB-C charger temperature monitoring, and industrial HVAC thermostat sensing requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for TMP6431DYAT 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 company headquartered in Dallas, Texas, designing and manufacturing analog, embedded processing, and logic products for industrial, automotive, and consumer markets.

The TMP64 series was developed to replace NTC thermistors in high-reliability temperature sensing, delivering linear PTC behavior, built-in fail-safe operation, and simplified system-level calibration for thermal management in power electronics and smart devices.

FAQ

What is the maximum operating temperature for TMP6431DYAT?

The TMP6431DYAT supports continuous operation from –40 °C to +150 °C when used in the SOT-5X3 (DYA) package, as confirmed in Section 7.3 of the SNIS212C datasheet. This rating exceeds the +125 °C limit of the X1SON (DEC) variant and is validated for 600-hour reliability testing at 150 °C with ±0.2% resistance drift.

Does TMP6431DYAT require external linearization circuitry?

No, TMP6431DYAT does not require external linearization circuitry. Its silicon-based PTC structure delivers inherently linear resistance vs. temperature behavior across –40 °C to +150 °C, enabling direct use with polynomial or lookup-table conversion - unlike NTC thermistors that demand parallel resistors or complex calibration.

What is the recommended bias configuration for TMP6431DYAT?

The recommended bias configuration for TMP6431DYAT is a voltage divider with a 47-kΩ top resistor (R_Bias) and V_Bias tied to the ADC reference voltage. This ratiometric setup cancels supply tolerance errors. Alternatively, a precision 100-µA current source yields higher sensitivity (≈40 mV/°C) and full ADC utilization, as detailed in Section 9.2.1.2 of the datasheet.

How does the fail-safe mechanism work in TMP6431DYAT?

The TMP6431DYAT's fail-safe mechanism relies on its positive temperature coefficient: during a short-to-supply fault, rising current causes self-heating, which increases resistance and inherently limits further current flow - preventing thermal runaway. In contrast, an NTC would decrease resistance under the same condition, accelerating failure.

Is TMP6431DYAT pin-compatible with other TMP64 variants?

TMP6431DYAT shares identical 2-pin SOT-5X3 (DYA) pinout and polarity (pin 1 = –, pin 2 = +) with all other DYA-packaged TMP64 variants (e.g., TMP6411DYAT, TMP6431DYAT), making them mechanically and electrically interchangeable on the same PCB footprint - though R25 and temperature range differ between models.