Texas Instruments LM20C-EVAL

Overview

LM20C-EVAL from Texas Instruments (formerly National Semiconductor) is an evaluation board designed to demonstrate the LM20C analog-output CMOS temperature sensor in SC70-5 package. It supports full-range operation from −30°C to +130°C at 2.4 V supply, delivers ±5°C accuracy at extremes, features <10 µA quiescent current, and enables rapid prototyping of thermal monitoring in battery-powered portable electronics.

For engineers reviewing the LM20C-EVAL datasheet, LM20C-EVAL pinout, LM20C-EVAL application, or LM20C-EVAL equivalent, this board provides validated signal conditioning, low-power biasing, and direct ADC interface capability - critical for validating thermal sensing performance before integration into cellular handsets, power modules, or disk drive thermal management subsystems.

Technical Context

The LM20C-EVAL implements a precision analog voltage-output temperature sensor reference design using the LM20C IC, which employs a parabolic transfer function VO = (−3.88×10⁻⁶×T²) + (−1.15×10⁻²×T) + 1.8639 V. It operates across 2.4 V–5.5 V supply with ≤10 µA quiescent current and supports load currents up to +16 µA while maintaining ≤2.5 mV load regulation error.

This evaluation platform includes on-board decoupling (0.1 µF V+–GND), optional RC filtering for noisy environments, and PCB layout optimized for minimal self-heating (θJA = 415°C/W for SC70). It does not include micro SMD variants - only SC70-5 socketed or soldered LM20C devices per ordering codes LM20CIM7/LM20CIM7X.

Key Specifications

Availability

LM20C-EVAL is available at Aetrix Electronics and suitable for thermal validation, embedded sensor qualification, and production-ready BOM development requiring stable component supply for portable electronics, power supply modules, and industrial control systems.

Supply support for LM20C-EVAL 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 acquired National Semiconductor in 2011 and maintains its precision analog portfolio, including high-accuracy temperature sensors and evaluation platforms for embedded thermal monitoring.

The LM20C-EVAL belongs to TI's legacy National Semiconductor temperature sensor evaluation suite, purpose-built to accelerate design-in of low-power analog-output thermal sensing in space-constrained, battery-operated applications.

FAQ

What is the primary function of the LM20C-EVAL evaluation board?

The LM20C-EVAL evaluation board is a dedicated hardware platform for characterizing and validating the LM20C analog-output temperature sensor. It provides a complete, tested circuit - including power conditioning, output buffering, and optional noise filtering - enabling engineers to verify voltage-vs-temperature linearity, accuracy, and system-level ADC interface behavior before committing to custom PCB layout. The LM20C-EVAL does not contain active processing; it serves solely as a sensor interface reference.

Which LM20 variant does the LM20C-EVAL support?

The LM20C-EVAL is configured for the LM20CIM7 and LM20CIM7X variants - SC70-5 packaged devices specified for ±5°C accuracy over −30°C to +130°C (at V+ = 2.4 V) or −55°C to +130°C (at V+ ≥ 2.7 V). It does not support the micro SMD LM20S variants (TLA04ZZA) or higher-accuracy LM20B versions, as their package footprints and thermal characteristics differ.

Does the LM20C-EVAL include onboard calibration or digital conversion?

No, the LM20C-EVAL contains no calibration circuitry, microcontroller, or ADC. It is a passive analog interface board that exposes the raw LM20C output voltage for external measurement. Users must apply the documented parabolic equation VO = (−3.88×10⁻⁶×T²) + (−1.15×10⁻²×T) + 1.8639 V to convert measured voltage to temperature. The LM20C-EVAL itself performs no computation or compensation.

Can the LM20C-EVAL operate from a single Li-ion cell?

Yes - the LM20C-EVAL supports direct connection to a single Li-ion cell (nominal 3.7 V, range ~2.7–4.2 V), fully within the LM20C's 2.4 V–5.5 V supply range. At 3.7 V, the board validates the LM20C's ±5°C accuracy across −55°C to +130°C, ≤10 µA quiescent draw, and stable analog output without regulation or shutdown circuitry - making it ideal for battery-life-critical designs like cellular phones and portable HDDs.

Is light exposure a concern when using the LM20C-EVAL?

Only if the LM20C device mounted on the LM20C-EVAL is the micro SMD variant - but the LM20C-EVAL board is designed exclusively for SC70-5 packages (MAA05A), which are not light-sensitive. The LM20C-EVAL documentation and layout do not address photovoltaic effects because the supported SC70 package has opaque molding compound. Light sensitivity applies solely to the TLA04ZZA micro SMD variant, which is incompatible with this board.