Texas Instruments LMT86LP

Overview

LMT86LP from Texas Instruments is a precision analog CMOS temperature sensor in TO-92 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-designed for off-board thermal monitoring in smoke detectors and battery-powered drone systems.

For engineers reviewing the LMT86LP datasheet, LMT86LP pinout, LMT86LP application, or LMT86LP equivalent, key selection criteria include its fast thermal time constant (10 s typical at 1.2 m/s airflow), push-pull output with ±50 µA drive, short-circuit protection, and footprint compatibility with LM20/LM35-critical for legacy replacement and low-power sensing architectures.

Technical Context

The LMT86LP implements a forward-biased base-emitter junction as its sensing element, buffered by a rail-to-rail NMOS/PMOS amplifier with push-pull output stage-enabling direct ADC interface without external buffering. Its transfer function follows a slight parabolic shape (–0.00347 mV/°C²), accurately modeled in Table 7-1 across the full range.

Thermal response is optimized via direct die-to-GND thermal path: the GND pin serves as both electrical ground and primary heat conduction path, yielding R_θJA = 167°C/W for LP package. Self-heating error remains below 0.015°C at 5 V/5.4 µA due to ultra-low power dissipation.

Key Specifications

Pinout & Package

Package: TO-92 (LP), through-hole, straight leads, body size 4.30 mm × 3.50 mm, GND pin thermally connected to die backside for optimal thermal conduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMT86LPG, the LMT86LP trades slightly slower thermal response for greater mechanical robustness and ease of hand-soldering; versus LMT85LP, it delivers higher sensitivity and tighter accuracy at the cost of higher minimum supply voltage-making LMT86LP optimal for 2.2–5.5 V systems requiring precision and reliability.

Availability

LMT86LP is available at Aetrix Electronics and suitable for smoke and heat detectors, drone battery monitoring, and automotive infotainment systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LMT86LP 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, embedded processing, and power management ICs, with decades of expertise in precision sensing and automotive-grade reliability.

The LMT86 family was designed specifically for high-accuracy, low-power analog temperature sensing in harsh environments-from under-hood automotive to battery-powered IoT endpoints-emphasizing thermal fidelity, supply flexibility, and robust packaging.

FAQ

What is the thermal time constant of the LMT86LP, and how is it measured?

The LMT86LP has a thermal time constant of 10 seconds typical under 1.2 m/s airflow, measured as the time required to reach 63.2% of final temperature when exposed to a step change in ambient temperature. This value is validated per JEDEC JESD51-13 using standardized test fixtures and airflow conditions, and applies specifically to the TO-92 LP package configuration-not other variants like LMT86LPG or LMT86DCK.

Does the LMT86LP require an external bypass capacitor on VDD?

The LMT86LP does not require a bypass capacitor for basic operation, but TI recommends a 0.01 µF ceramic capacitor placed within 5 mm of the VDD pin in noisy environments or when sharing supply rails with switching regulators or digital ICs. This reduces supply-noise coupling to the output, as the LMT86LP exhibits measurable supply-noise gain-especially above 10 kHz-as documented in Figure 6-8 of the SNIS169F datasheet.

Can the LMT86LP be powered directly from a microcontroller GPIO pin?

Yes-the LMT86LP can be powered directly from a microcontroller GPIO pin because its maximum supply current is 9 µA (at 150°C), well within typical GPIO sourcing capability (≥2 mA). This enables simple shutdown control: driving the GPIO low disconnects VDD and reduces total system current to near-zero, making LMT86LP ideal for battery-powered applications requiring aggressive power cycling.

What is the meaning of "footprint compatible with LM20/LM35" for the LMT86LP?

"Footprint compatible" means the LMT86LP in TO-92 LP package uses identical lead spacing (2.54 mm pitch), body outline, and pin numbering (VDD–OUT–GND) as standard LM20 and LM35 TO-92 variants-allowing direct PCB replacement without layout modification. However, electrical behavior differs: LMT86LP outputs inverse voltage (–10.9 mV/°C) vs. LM35's positive slope (+10 mV/°C), requiring firmware sign inversion or ADC offset adjustment.

How does the LMT86LP handle capacitive loads on its output pin?

The LMT86LP drives capacitive loads up to 1100 pF without external compensation, as verified in Figure 7-1 of the datasheet. For loads exceeding 1100 pF-such as long traces or high-input-capacitance ADCs-a series resistor (e.g., 1.5 kΩ for 100–999 nF) must be added between OUT and the load to ensure stability and prevent ringing, per Table 7-2. This preserves monotonicity and avoids measurement errors caused by output overshoot.