Texas Instruments TMP431CDGKT

Overview

TMP431CDGKT from Texas Instruments is a dual-channel digital temperature sensor IC featuring one local die temperature channel and one remote junction temperature channel, ±1°C accuracy (0°C–100°C), SMBus 2.0/Two-Wire interface, and automatic beta compensation for PNP/NPN transistors - used in processor and FPGA thermal monitoring within servers and industrial controllers.

For engineers reviewing the TMP431CDGKT datasheet, TMP431CDGKT pinout, TMP431CDGKT application, or TMP431CDGKT equivalent, key selection considerations include its VSSOP-8 package, 2.7–5.5 V supply range, 12-bit resolution (0.0625°C), open-drain ALERT/THERM2 and THERM outputs, and support for series resistance cancellation up to 1 kΩ with beta correction disabled.

Technical Context

The TMP431CDGKT implements a dedicated analog front-end with programmable current sources (6–120 μA) for remote diode sensing, integrated ADC with 12-bit resolution per channel, and on-chip oscillator for conversion timing control. Its beta compensation logic dynamically selects optimal collector current ranges (beta = 0.1 to 27) at each conversion start to maintain accuracy across transistor process variations.

It supports extended temperature measurement range (–64°C to 191°C) via configuration register bit 2, stores min/max temperature values in dedicated registers, and provides two independent thermal alert outputs (ALERT/THERM2 and THERM) with user-programmable thresholds - all accessible over SMBus with write byte, read byte, send byte, and receive byte commands.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.00 mm × 3.00 mm body, 0.65 mm lead pitch, exposed thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM75BIMM/NOPB and MAX6642AESA+, the TMP431CDGKT uniquely delivers ±1°C remote accuracy without calibration, automatic beta adaptation, and SMBus-compliant alert handling - making it the only option supporting unattended thermal validation in high-reliability compute and industrial systems.

Availability

TMP431CDGKT is available at Aetrix Electronics and suitable for server thermal management, industrial PLC controllers, and FPGA-based telecom equipment requiring stable component supply across extended product lifecycles.

Supply support for TMP431CDGKT 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, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The TMP43x family was designed specifically for high-accuracy, calibration-free thermal monitoring of processors, FPGAs, and power semiconductors in space-constrained, thermally demanding systems - emphasizing SMBus interoperability and robustness against PCB parasitics.

FAQ

What is the maximum remote temperature measurement range supported by the TMP431CDGKT?

The TMP431CDGKT supports an extended remote temperature measurement range of –64°C to 191°C when configured via bit 2 of Configuration Register 1. However, practical accuracy remains ±1°C only within –40°C to 150°C for the remote diode sensor, as validated across multiple transistor manufacturers. The local sensor is specified from –40°C to 125°C. The TMP431CDGKT's extended range mode uses offset binary encoding (adding 0x40 to standard values) to represent sub-zero temperatures.

Does the TMP431CDGKT require external calibration for remote temperature measurements?

No, the TMP431CDGKT does not require external calibration for remote temperature measurements. It achieves ±1°C accuracy (0°C–100°C) across multiple device manufacturers through automatic beta compensation, η-factor correction, and series resistance cancellation - all implemented in hardware. These features adapt to transistor process variations and PCB layout parasitics without user intervention. The TMP431CDGKT performs full self-compensation at every conversion cycle.

How many remote temperature channels does the TMP431CDGKT support?

The TMP431CDGKT supports exactly one remote temperature channel, implemented via the DXP and DXN pins. This distinguishes it from the pin-compatible TMP432 (VSSOP-10), which provides two remote channels (DXP1/DXN1 and DXP2/DXN2). Both devices share the same local temperature sensor and SMBus register map, but the TMP431CDGKT's single remote channel simplifies routing and reduces BOM count in cost-sensitive, single-processor applications.

What are the SMBus interface requirements for the TMP431CDGKT?

The TMP431CDGKT requires SMBus 2.0–compliant pullup resistors on SCL and SDA (typically 2.2 kΩ to V+), supports clock frequencies up to 3.4 MHz, and implements SMBus Alert Response Address (ARA) protocol for interrupt-driven communication. It accepts SMBus write byte, read byte, send byte, and receive byte commands. The device has programmable slave addresses and supports timeout detection (25–35 ms). The TMP431CDGKT's VOL is 0.4 V max at 6 mA sink, matching standard SMBus voltage thresholds.

Can the ALERT and THERM outputs of the TMP431CDGKT be used simultaneously?

Yes, the TMP431CDGKT supports simultaneous use of both ALERT and THERM outputs. ALERT (pin 6) is configurable as either an SMBus alert flag or a second thermal flag (THERM2) via Configuration Register 1. THERM (pin 4) is fixed as a dedicated thermal alert output. Both are open-drain, active-low, and can be wire-OR'd with other devices on the same bus. Their thresholds are independently programmable, enabling hierarchical thermal response - e.g., THERM triggers fan ramp-up while ALERT initiates processor throttling.