Texas Instruments LMT86LPG

Overview

LMT86LPG from Texas Instruments is a precision analog CMOS temperature sensor in TO-92S through-hole package, delivering ±0.4°C typical accuracy over –50°C to 150°C, –10.9 mV/°C output slope, 2.2 V minimum supply voltage, and 5.4 µA quiescent current - ideal for off-board thermal monitoring in smoke detectors and heat-sensing modules.

For engineers reviewing the LMT86LPG datasheet, LMT86LPG pinout, LMT86LPG application, or LMT86LPG equivalent, key selection criteria include its fast 10 s thermal time constant (1.2 m/s airflow), push-pull output with ±50 µA drive capability, short-circuit protection, and footprint compatibility with LM20/LM35 sensors in space-constrained industrial and automotive thermal sensing designs.

Technical Context

The LMT86LPG implements a forward-biased base-emitter junction as its sensing element, buffered by a rail-to-rail CMOS amplifier with push-pull output stage - enabling low-impedance analog voltage output inversely proportional to temperature. Its transfer function follows a well-characterized parabolic shape, with reference values tabulated across –50°C to 150°C in the official transfer table.

Thermal response is optimized via direct die-to-GND thermal path in the TO-92S package (R_θJA = 130.4°C/W), supporting rapid ambient tracking in airflow-sensitive applications. Self-heating error remains below 0.014°C at 5 V supply and 30°C ambient due to ultra-low 5.4 µA supply current and minimal power dissipation.

Key Specifications

Pinout & Package

TO-92S (LPG) is a 3-pin through-hole plastic package with straight leads, 4.00 mm × 3.15 mm body size, and direct die attachment to GND pin for enhanced thermal conduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMT86LPG, LMT85LP offers lower supply voltage flexibility but sacrifices 23% output sensitivity, while LM20LPG reduces accuracy by >6× and increases power draw - making LMT86LPG the optimal choice for applications demanding both high fidelity and ultra-low power in rugged through-hole form factor.

Availability

LMT86LPG is available at Aetrix Electronics and suitable for smoke and heat detectors, automotive powertrain systems, drone battery management, and smart appliance motor protection requiring stable component supply across extended product lifecycles.

Supply support for LMT86LPG 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, power management, and signal chain solutions.

The LMT86 family was designed specifically for high-accuracy, low-power analog temperature measurement in industrial, automotive, and consumer systems - emphasizing thermal responsiveness, supply flexibility, and robust packaging for real-world mounting conditions.

FAQ

What is the thermal time constant of the LMT86LPG and how is it measured?

The LMT86LPG has a thermal time constant of 10 seconds under 1.2 m/s airflow, defined as the time required to reach 63.2% of final temperature in a step-change environment. This value is measured per JEDEC JESD51-13 using standardized airflow conditions and reflects the TO-92S package's optimized thermal mass and lead-frame design - critical for applications like fire detection where rapid transient response is mandatory. The LMT86LPG achieves this performance without external heatsinking or thermal compound.

Does the LMT86LPG require external decoupling capacitors on its VDD pin?

The LMT86LPG does not require external decoupling capacitors under typical low-noise conditions, thanks to its ultra-low 5.4 µA supply current and internal regulation. However, TI recommends placing a 0.01 µF ceramic capacitor within 5 cm of the VDD pin in electrically noisy environments (e.g., near switching regulators or motor drivers) to suppress supply ripple that could couple into the analog output. This guidance is confirmed in Section 9 of the LMT86LPG datasheet and validated in Figure 6-8 (supply-noise gain vs frequency).

Can the LMT86LPG be used in automotive under-hood applications?

Yes, the LMT86LPG is qualified for operation from –50°C to +150°C and features robust ESD protection (±2500 V HBM), making it suitable for non-safety-critical under-hood locations such as ECU ambient sensing or transmission fluid temperature proxy monitoring. While the standard LMT86LPG is not AEC-Q100 certified, its thermal and electrical specifications align with many Tier-2 automotive thermal monitoring requirements - and TI offers the automotive-grade LMT86DCK-Q1 variant for fully qualified applications.

How does the LMT86LPG's output voltage relate to temperature, and what is its linearity behavior?

The LMT86LPG outputs a voltage inversely proportional to temperature, with a nominal slope of –10.9 mV/°C across –30°C to +90°C. Its transfer function exhibits slight parabolic nonlinearity (umbrella-shaped error curve), with peak error of ±2.7°C over the full range - detailed in Table 7-1 of the datasheet. For most applications, the linear approximation suffices; for highest accuracy, users can apply the provided parabolic equation or use the 151-point lookup table downloadable from TI's LMT86 product folder.

Is the LMT86LPG pin-compatible with the LM35 temperature sensor?

Yes, the LMT86LPG is footprint-compatible and functionally interoperable with the LM35 in TO-92 packages: both use identical 3-pin TO-92S pinout (VDD–OUT–GND), share similar output voltage ranges (LM35: 0–1 V at 0–100°C; LMT86LPG: ~2100–1300 mV at 0–70°C), and require no external components. However, the LMT86LPG operates down to 2.2 V (vs LM35's 4 V min) and delivers ±0.4°C accuracy versus LM35's ±0.5°C - making it a true performance and power upgrade with no layout changes required.