Texas Instruments TMP6431DECR

Overview

TMP6431DECR from Texas Instruments is a silicon-based linear positive temperature coefficient (PTC) thermistor in a 0402-compatible X1SON package, delivering ±1% R25 tolerance (47 kΩ at 25 °C), 6400 ppm/°C TCR at 25 °C, and operation from –40 °C to +125 °C. It enables high-accuracy temperature monitoring in space-constrained motor control, charger thermal threshold detection, and display backlight compensation circuits without external linearization.

For engineers reviewing the TMP6431DECR datasheet, TMP6431DECR pinout, TMP6431DECR application, or TMP6431DECR equivalent, key selection criteria include its linear R–T response across –40 °C to 125 °C, fast 0.6 s thermal response in stirred liquid, built-in short-circuit fail-safe behavior, and compatibility with ratiometric voltage-divider or precision current-source biasing topologies.

Technical Context

The TMP6431DECR operates as a two-terminal passive PTC resistive element whose resistance increases linearly with temperature. Its silicon process ensures consistent TCR of 6400 ppm/°C at 25 °C with ±0.2% typical tolerance across –40 °C to 125 °C, eliminating need for NTC-style linearization circuitry or multi-point calibration.

It requires a positive bias (pin 2 at higher potential than pin 1) and supports maximum 5.5 V across terminals and 100 µA sense current. Self-heating is minimized by low thermal mass and 0.5% typical long-term drift after 600 h at 150 °C, enabling stable performance in industrial and automotive thermal management systems.

Key Specifications

Pinout & Package

TMP6431DECR uses a 2-pin X1SON (DEC) package measuring 0.60 mm × 1.00 mm, footprint-compatible with industry-standard 0402 (inch) land patterns. The device has no internal active circuitry-only a silicon PTC resistive element with polarized terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMP6431DECR, TMP61DECR provides lower R25 for reduced Johnson noise and higher signal-to-noise ratio in low-voltage systems, while TMP64DYAR extends usable ambient range to 150 °C with trade-offs in size and thermal response time-neither is pin-compatible, but both share identical functional behavior and design tool support.

Availability

TMP6431DECR is available at Aetrix Electronics and suitable for motor control thermal monitoring, charger overtemperature protection, and display backlight thermal compensation requiring stable component supply, full traceability, and lifecycle continuity.

Supply support for TMP6431DECR 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 specializing in analog and embedded processing technologies, with leadership in precision sensing, power management, and signal chain solutions.

TMP6431DECR belongs to the TMP6x linear silicon thermistor family, designed specifically to replace NTC thermistors in high-reliability temperature sensing applications where linearity, long-term stability, and fail-safe behavior are critical.

FAQ

What is the exact package type and dimensions of TMP6431DECR?

TMP6431DECR uses the X1SON package (also labeled DEC), with nominal body dimensions of 0.60 mm × 1.00 mm and a 2-pin configuration. It is footprint-compatible with standard 0402 (inch) land patterns, enabling drop-in replacement in space-constrained designs without PCB revision.

Does TMP6431DECR require external linearization circuitry like traditional NTC thermistors?

No. TMP6431DECR exhibits a linear resistance-vs.-temperature curve across –40 °C to 125 °C, with a consistent 6400 ppm/°C TCR. This eliminates the need for parallel linearization resistors, midpoint calibration, or complex piecewise interpolation-enabling direct use with simple voltage-divider or current-source biasing.

What is the maximum allowable bias voltage and current for reliable operation of TMP6431DECR?

TMP6431DECR supports a maximum voltage of 6 V across its terminals (absolute maximum) and 5.5 V under recommended operating conditions. The maximum sense current is 100 µA; typical operation uses 42.553 µA for optimal TCR stability and minimal self-heating, as specified in the electrical characteristics table.

How does the built-in fail-safe behavior of TMP6431DECR improve system safety compared to NTC thermistors?

Under short-to-supply conditions, TMP6431DECR's positive temperature coefficient causes resistance to increase with rising temperature, inherently limiting current and preventing thermal runaway. In contrast, an NTC's resistance decreases under self-heating, creating a destructive positive feedback loop-making TMP6431DECR safer in overtemperature fault scenarios.

Can TMP6431DECR be used with a microcontroller's internal ADC without external precision references?

Yes. When TMP6431DECR is used in a voltage-divider configuration with a 47-kΩ bias resistor and the same supply rail powers both the divider and the MCU's ADC reference (ratiometric design), voltage source tolerances cancel out. This allows accurate temperature measurement using only the MCU's internal reference and ADC-no external precision voltage reference is required.