Texas Instruments TMP6431QDECTQ1

Overview

TMP6431QDECTQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-grade silicon linear thermistor with positive temperature coefficient (PTC), 47-kΩ nominal resistance at 25 °C (±1% tolerance over 0 °C to 70 °C), 6400 ppm/°C TCR at 25 °C, and fast 0.6 s thermal response in stirred liquid. It operates from –40 °C to 125 °C and is used for precision thermal monitoring in battery management systems and motor control circuits.

For engineers reviewing the TMP6431QDECTQ1 datasheet, TMP6431QDECTQ1 pinout, TMP6431QDECTQ1 application, or TMP6431QDECTQ1 equivalent, key selection considerations include its linear R–T behavior eliminating NTC linearization circuitry, built-in short-circuit fail-safe, ±0.2% typical TCR tolerance across temperature, and compatibility with ratiometric ADC interfaces using a 47-kΩ bias resistor.

Technical Context

The TMP6431QDECTQ1 implements a monolithic silicon PTC structure where doping and active region geometry define both R25 and TCR. Its resistance increases linearly with temperature, enabling direct polynomial or lookup-table-based temperature conversion without external linearization components. The device requires proper polarity: pin 2 (+) must be at higher potential than pin 1 (–).

It operates within 0–5.5 V bias voltage and 0–100 µA sense current, with self-heating minimized by low thermal mass and 443.4 °C/W junction-to-ambient thermal resistance in the X1SON (DEC) package. Built-in fail-safe behavior limits current during short-to-supply events via inherent PTC resistance rise.

Key Specifications

Pinout & Package

The TMP6431QDECTQ1 is housed in a 2-pin X1SON package (0.60 mm × 1.00 mm), footprint-compatible with standard 0402 (inch) land patterns. This ultra-compact surface-mount design enables placement directly adjacent to heat-generating components for minimal thermal lag.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMP6431QDECTQ1, TMP6411QDECTQ1 offers identical performance at lower cost but lacks Grade 0 qualification, while TMP6431QDYAQ1 provides extended temperature range in a mechanically distinct package-requiring layout revision but enabling use in hotter zones like DC-DC converter primary-side heatsinks.

Availability

TMP6431QDECTQ1 is available at Aetrix Electronics and suitable for battery management systems, motor control inverters, on-board chargers, and display backlight thermal compensation requiring stable component supply across automotive production lifecycles.

Supply support for TMP6431QDECTQ1 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, embedded processing, and automotive electronics, with decades of leadership in precision sensing and power management ICs.

The TMP6 series was designed specifically for automotive thermal sensing applications requiring linearity, long-term stability, and AEC-Q100 compliance-replacing legacy NTCs with simplified signal chains and enhanced reliability.

FAQ

What is the maximum operating temperature of the TMP6431QDECTQ1?

The TMP6431QDECTQ1 is AEC-Q100 Grade 1 qualified for continuous operation from –40 °C to 125 °C. Its X1SON (DEC) package supports this full range, and absolute maximum junction temperature is rated at 155 °C per the datasheet's Absolute Maximum Ratings table. Operation beyond 125 °C is not supported for Grade 1 compliance, though short-duration excursions may occur without immediate failure.

Does the TMP6431QDECTQ1 require external linearization circuitry?

No, the TMP6431QDECTQ1 does not require external linearization circuitry. Its silicon-based PTC structure delivers inherently linear resistance vs. temperature behavior across –40 °C to 125 °C, with ±0.2% typical TCR tolerance. This eliminates the need for parallel resistors or complex calibration algorithms required by NTC thermistors-simplifying both hardware design and firmware implementation for the TMP6431QDECTQ1.

How is polarity critical for correct operation of the TMP6431QDECTQ1?

Polarity is critical because the TMP6431QDECTQ1 has polarized terminals: pin 1 is (–) and pin 2 is (+). The (+) terminal must be held at a higher voltage potential than the (–) terminal to ensure proper PTC behavior and built-in fail-safe function. Reversing polarity can cause inaccurate readings, increased self-heating, and loss of short-circuit protection-so correct orientation must be verified during PCB layout and assembly for the TMP6431QDECTQ1.

Can the TMP6431QDECTQ1 be used with a ratiometric ADC configuration?

Yes, the TMP6431QDECTQ1 is explicitly designed for ratiometric ADC use. When the bias voltage (e.g., 3.3 V or 5 V) is shared with the ADC reference voltage, supply tolerance errors cancel-enabling high-accuracy temperature measurement without trimming. This configuration is validated in the datasheet's Figure 9-2 and Section 9.2.1.2, and is a key advantage of the TMP6431QDECTQ1 over non-ratiometric alternatives.

What is the thermal response time of the TMP6431QDECTQ1 in still air?

The TMP6431QDECTQ1 exhibits a thermal response time of 3.2 seconds to reach 63% of ΔT when transitioning from 25 °C to 70 °C in still air. This value is measured per JEDEC JESD51-13 and reflects real-world convection-limited conditions on standard PCBs. For faster response, forced airflow or placement in stirred liquid reduces this to 0.6 s-making the TMP6431QDECTQ1 suitable for both steady-state monitoring and dynamic thermal event detection.