Texas Instruments TMP435ADGST

Overview

TMP435ADGST from Texas Instruments is a dual-channel digital temperature sensor IC with ±1°C local and remote diode junction accuracy, SMBus 2.0 interface, and integrated beta compensation for PNP/NPN transistors or diodes. It operates from 2.7V to 5.5V, delivers 12-bit resolution (0.0625°C), and supports extended temperature measurement from –55°C to +150°C in server CPU thermal monitoring applications.

For engineers reviewing the TMP435ADGST datasheet, TMP435ADGST pinout, TMP435ADGST application, or TMP435ADGST equivalent, key selection criteria include remote diode error tolerance across manufacturers, SMBus timeout compliance (25–35 ms), series resistance cancellation capability (up to 1 kΩ), and open-drain ALERT/THERM2 output configuration for wired-OR thermal flagging.

Technical Context

The TMP435ADGST implements collector-current-controlled remote sensing to auto-compensate for transistor beta variation across temperature, supporting n-factor correction (1.000–1.008) and programmable beta range (0.1–27). Its dual-channel architecture independently measures die temperature (local) and external junction temperature (remote) using separate 12-bit ADCs with configurable conversion rates (0.0625–8 conversions/s).

It features two independent thermal alert outputs-ALERT (reconfigurable as THERM2) and dedicated THERM-with user-programmable high/low limits per channel, plus status registers for OPEN fault detection, BUSY indication, and RTHRM/LTHRM flags. All registers are accessed via SMBus-compatible write/read byte and send/receive byte commands.

Key Specifications

Pinout & Package

Package: MSOP-10 (DGS), 3.0 mm × 3.0 mm × 1.0 mm body, exposed pad optional for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMP435ADGST, TMP451AIRTER offers superior remote accuracy and embedded calibration but increases power and reduces configurability; LM95235CIMMX provides SPI simplicity at the cost of reduced precision, missing SMBus features, and no automatic beta handling - making TMP435ADGST optimal for SMBus-based, multi-vendor thermal systems requiring robust diode compensation.

Availability

TMP435ADGST is available at Aetrix Electronics and suitable for server thermal management, industrial PLCs, FPGA carrier boards, and medical power modules requiring stable component supply across extended temperature ranges and multi-source manufacturing environments.

Supply support for TMP435ADGST 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 TMP435 product line was designed specifically for high-accuracy, multi-point thermal monitoring in computing and industrial systems where remote diode sensing must remain reliable across process variations, packaging differences, and long interconnects.

FAQ

What is the maximum remote temperature measurement range supported by the TMP435ADGST?

The TMP435ADGST supports a remote temperature measurement range of –55°C to +150°C when configured in extended mode via the RANGE bit in Configuration Register 1. This mode uses extended binary encoding with a –64°C offset and is validated for use with standard silicon diodes and PNP transistors across that full span. The local channel is specified from –40°C to +125°C.

Does the TMP435ADGST require external calibration for different transistor types?

No, the TMP435ADGST does not require external calibration for different transistor types. It performs automatic beta compensation and n-factor correction internally, supporting both diode-connected and GND-collector PNP configurations. The device detects beta characteristics at startup and selects appropriate correction parameters - enabling out-of-box accuracy across Intel, AMD, and FPGA vendor diodes without per-unit trimming.

How does the TMP435ADGST handle series resistance in the remote sensor path?

The TMP435ADGST cancels series resistance in the DXP/DXN path automatically: up to 1 kΩ when beta correction is disabled (Configuration Register 2, RC = 0111), or up to 300 Ω when enabled (RC = 1xxx). This cancellation occurs during each conversion cycle and eliminates temperature offset caused by PCB trace resistance or connector contact resistance - a critical capability for long-sensor routing in rack-mounted servers.

Can the ALERT and THERM2 pins on the TMP435ADGST be used simultaneously as independent thermal flags?

Yes, the ALERT and THERM2 pins on the TMP435ADGST can operate as independent thermal flags. By default, ALERT functions as the primary alarm output and THERM2 is configurable as a secondary thermal flag via Configuration Register 1 (AL/TH bit). Both outputs are open-drain, active-low, and driven by separate comparator logic tied to user-programmable high/low limits - allowing distinct thermal responses for local overtemperature and remote overtemperature events.

What SMBus commands are supported by the TMP435ADGST for reading temperature data?

The TMP435ADGST supports SMBus Write Byte, Read Byte, Send Byte, and Receive Byte commands. Temperature data is accessed by first writing the Pointer Register (address 00h for local high byte, 01h for remote high byte), then performing sequential Read Byte operations to retrieve high and low bytes. Two-byte read commands (e.g., from address 00h) are also supported to fetch full 16-bit temperature values in a single transaction.