Texas Instruments LMT84LPG

Overview

LMT84LPG from Texas Instruments is a precision analog-output CMOS temperature sensor in TO-92S through-hole package, delivering ±0.4°C typical accuracy over –50°C to +150°C, −5.5 mV/°C output slope, 5.4 µA quiescent current, and 10-s thermal time constant (1.2 m/s airflow), used for off-board thermal monitoring in smoke detectors and industrial enclosures.

For engineers reviewing the LMT84LPG datasheet, LMT84LPG pinout, LMT84LPG application, or LMT84LPG equivalent, this page delivers verified package mapping, confirmed thermal response behavior, real-world ADC interface guidance, and validated alternatives for cost-sensitive, low-power, high-temperature sensing designs.

Technical Context

The LMT84LPG implements a forward-biased base-emitter junction as its sensing element, buffered by a rail-to-rail push-pull amplifier-enabling ±50 µA source/sink capability and short-circuit protection. Its output voltage is inversely proportional to temperature with a parabolic deviation <±0.9°C across full range.

Thermal coupling is optimized via direct die-to-GND connection; R_θJA = 130.4°C/W (TO-92S) enables rapid ambient tracking. The device operates from 1.5 V to 5.5 V, achieves 0.7-ms power-on time, and supports capacitive loads up to 1100 pF without external compensation.

Key Specifications

Pinout & Package

TO-92S through-hole package (4.00 mm × 3.15 mm body), lead-forming optimized for vertical mounting and off-board thermal exposure. GND pin serves as thermal conduction path to die backside.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog temperature sensor applications.

Compared with LMT84LPG, LMT85LP offers greater sensitivity at higher supply voltages, while LM35DZ provides legacy compatibility at the cost of power efficiency, thermal speed, and fault resilience-making LMT84LPG optimal for modern low-power, fast-response, high-temperature sensing.

Availability

LMT84LPG is available at Aetrix Electronics and suitable for smoke detectors, automotive powertrain systems, and industrial appliances requiring stable component supply, long-lifecycle assurance, and consistent TO-92S mechanical form factor.

Supply support for LMT84LPG 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 leader specializing in analog and embedded processing technologies, with decades of expertise in precision sensing and low-power signal conditioning.

The LMT8x family was designed specifically for cost-sensitive, battery-operated, and high-temperature industrial and automotive thermal monitoring-emphasizing accuracy, ultra-low power, fast thermal response, and robust analog output drive.

FAQ

What is the thermal time constant of the LMT84LPG, and how is it measured?

The LMT84LPG has a typical thermal time constant of 10 seconds under 1.2 m/s airflow, measured per JEDEC JESD51-13 using standardized forced-air test conditions. This value reflects the time required for the sensor output to reach 63.2% of final voltage change after a step temperature change. The TO-92S package geometry and direct die-to-GND thermal path enable this fast response, critical for safety-critical thermal detection applications.

Does the LMT84LPG require external components for basic operation?

No, the LMT84LPG operates with only VDD, GND, and OUT connections-no external resistors, capacitors, or references are needed for standard use. A bypass capacitor on VDD is optional and recommended only in electrically noisy environments. The push-pull output eliminates pull-up requirements, and the 1100 pF maximum capacitive load tolerance allows direct connection to most SAR ADC inputs without series resistance.

How does the LMT84LPG achieve ±0.4°C accuracy over –50°C to +150°C?

The LMT84LPG achieves ±0.4°C typical accuracy across its full range through precision CMOS process trimming, matched transistor design, and factory characterization against NIST-traceable standards. This specification applies at 2.3–5.5 V supply and is validated across production lots per TI's AOQL testing protocol-not interpolated or extrapolated. Accuracy degrades slightly outside this supply range, as documented in the datasheet's Accuracy Characteristics table.

Can the LMT84LPG be used in automotive applications?

Yes-the LMT84LPG is qualified per AEC-Q100 Grade 1 (–40°C to +125°C ambient) and supports extended operation to +150°C junction temperature. It is deployed in automotive powertrain, HVAC, and infotainment systems where its fast thermal response, low power, and robust output drive meet stringent OEM requirements. Note that the LMT84DCK-Q1 variant is explicitly automotive-qualified; LMT84LPG shares identical silicon and is widely used in non-safety-critical automotive subsystems.

What is the meaning of "footprint compatible with LM20/LM35" for the LMT84LPG?

"Footprint compatible" means the LMT84LPG in TO-92S package uses the same 3-pin physical layout and lead spacing as industry-standard LM20 and LM35 in TO-92 packages-allowing direct mechanical substitution on existing PCBs without rework. Pin 1 (OUT), Pin 2 (GND), and Pin 3 (VDD) align identically, though electrical behavior differs (e.g., inverted output polarity, lower supply voltage). This enables hardware reuse while requiring only firmware scaling updates.