Texas Instruments LM20BIM7X

Overview

LM20BIM7X from Texas Instruments (formerly National Semiconductor) is a precision analog-output CMOS temperature sensor with ±2.5°C accuracy at −55°C to +130°C, 2.4V–5.5V supply range, and 10 µA max quiescent current. It delivers parabolic output voltage vs. temperature (VO = −3.88×10⁻⁶·T² − 1.15×10⁻²·T + 1.8639 V) and is used in battery-powered thermal monitoring for power supply modules and portable electronics.

For engineers reviewing the LM20BIM7X datasheet, LM20BIM7X pinout, LM20BIM7X application, or LM20BIM7X equivalent, key selection criteria include its SC70-5 package, low self-heating (<0.02°C), predictable curvature error, and compatibility with single-cell Li-ion systems requiring high-accuracy analog temperature feedback without digital conversion overhead.

Technical Context

The LM20BIM7X implements a monolithic CMOS bandgap-based temperature-to-voltage transducer with inherent parabolic transfer function-no external calibration required. Its output voltage spans 2485 mV at −55°C to 303 mV at +130°C, enabling direct ADC interfacing across full industrial range.

Thermal sensing relies on die-to-GND thermal conduction via pin 2; grounding this pin optimizes PCB heat sinking. The device operates without shutdown circuitry due to intrinsic ultra-low power (≤10 µA), permitting direct logic-gate powering and eliminating control-line overhead.

Key Specifications

Pinout & Package

LM20BIM7X uses the SC70-5 molded package (NS package number MAA05A), 2.0 mm × 2.1 mm × 0.9 mm body, with gull-wing leads. Pin 2 (GND) must be grounded for optimal thermal coupling to PCB ground plane; pin 1 (NC) is unconnected and must float or be grounded-no signal routing permitted.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM20CIM7X and TS331IYLT, the LM20BIM7X uniquely delivers calibrated analog voltage output with ±2.5°C accuracy across −55°C to +130°C, enabling precise closed-loop thermal management without digital sensor fusion or external signal conditioning.

Availability

LM20BIM7X is available at Aetrix Electronics and suitable for battery management systems, power supply modules, and portable computing devices requiring stable component supply, long-term lifecycle support, and consistent SC70-5 packaging.

Supply support for LM20BIM7X 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 full technical and manufacturing continuity for legacy analog sensors including the LM20 family.

The LM20BIM7X belongs to TI's precision analog temperature sensor product line, designed specifically for applications demanding low-power, high-accuracy analog thermal feedback without digital interface overhead or calibration complexity.

FAQ

What is the guaranteed accuracy specification for LM20BIM7X across its full temperature range?

The LM20BIM7X is specified for ±2.5°C maximum accuracy at both −55°C and +130°C when operated with V+ ≥ 2.7 V. At +30°C, accuracy is ±2.5°C max. This is confirmed in the Electrical Characteristics table under "Temperature to Voltage Error" for the LM20B grade. Accuracy degrades linearly toward the extremes but remains bounded by the ±2.5°C limit across the full −55°C to +130°C range.

Can LM20BIM7X operate from a single 3.0 V Li-ion battery throughout its discharge curve?

Yes. The LM20BIM7X supports supply voltages from +2.4 V to +5.5 V, covering the full operational range of a single Li-ion cell (3.0 V nominal, ~2.7–4.2 V typical). Its quiescent current remains ≤10 µA even at 2.4 V, ensuring stable analog output and minimal self-heating during deep discharge-critical for battery runtime integrity in portable designs.

What is the correct pin configuration and grounding strategy for LM20BIM7X in thermal-critical layouts?

The LM20BIM7X uses an SC70-5 package with pins: 1 (NC), 2 (GND), 3 (VO), 4 (V+), 5 (GND). For thermal accuracy, pin 2 must be soldered to a large PCB ground plane to minimize θJA (415°C/W). Pin 5 is internally tied to pin 2-both must connect to the same low-impedance ground net. NC pin 1 must float or be grounded; no signal routing is permitted.

Does LM20BIM7X require external components for basic operation?

No. The LM20BIM7X operates with only V+ and GND connections. A 0.1 µF bypass capacitor from V+ to GND is recommended for noise immunity, but not required for functionality. Output can drive ADC inputs directly-no buffer amplifier or filtering needed for loads ≤16 µA. Capacitive loads <300 pF require no additional compensation.

How does the parabolic transfer function of LM20BIM7X improve measurement accuracy versus linear approximations?

The LM20BIM7X's documented parabolic equation (VO = −3.88×10⁻⁶·T² − 1.15×10⁻²·T + 1.8639 V) reduces temperature error to ±2.5°C across −55°C to +130°C. Linear approximations introduce up to ±1.41°C deviation over the same range. Using the full parabolic model in firmware-or applying two-point linear calibration-enables system-level accuracy matching the device's native specification without hardware modification.