Texas Instruments LM20SIBPX

Overview

LM20SIBPX from Texas Instruments is a precision analog-output CMOS temperature sensor operating from 2.4 V to 5.5 V, delivering ±1.5°C accuracy at 30°C and ±3.5°C max error at 125°C, with 10 µA quiescent current and parabolic transfer function VO = (−3.88×10⁻⁶×T²) + (−1.15×10⁻²×T) + 1.8639 V - used for battery-powered thermal monitoring in portable electronics.

For engineers reviewing the LM20SIBPX datasheet, LM20SIBPX pinout, LM20SIBPX application, or LM20SIBPX equivalent, key selection criteria include its DSBGA-4 package footprint, −30°C to 125°C operating range at 2.4 V supply, predictable curvature compensation, low self-heating (<0.02°C), and compatibility with single-cell Li-ion systems.

Technical Context

The LM20SIBPX implements a forward-biased base-emitter junction as its sensing element, buffered by a Class-A amplifier to deliver low-impedance analog output (≤160 Ω) capable of sourcing up to 16 µA. Its transfer function is intentionally parabolic to minimize system-level calibration burden.

Operating voltage directly constrains temperature range: at 2.4 V, it supports −30°C to 125°C; at ≥2.7 V, −40°C to 125°C. Output voltage varies from ~2.485 V at −55°C to ~0.303 V at 130°C, with slope ≈ −11.77 mV/°C near 25°C and nonlinearity ≤±0.4% over −20°C to 80°C.

Key Specifications

Pinout & Package

LM20SIBPX uses a 4-pin DSBGA (YZR) package measuring 0.96 mm × 0.96 mm with 0.5-mm pitch, optimized for space-constrained portable designs. The die attach paddle is internally connected to GND for thermal conduction to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM20BIMHX/NOPB, LM20SIBPX trades −55°C capability for tighter ±1.5°C accuracy at 30°C and lower 10 µA supply current; versus TS3217-125IYDT, it avoids I²C dependency and reduces active power by 65%, at the cost of requiring host-side quadratic computation.

Availability

LM20SIBPX is available at Aetrix Electronics and suitable for portable battery management, industrial power module sensing, consumer appliance control, and embedded HVAC sensor nodes requiring stable component supply across long-lifecycle programs.

Supply support for LM20SIBPX 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 company specializing in analog and embedded processing technologies, with leadership in precision sensing, power management, and signal chain solutions.

The LM20 product line delivers low-power, high-accuracy analog temperature sensors for space- and energy-constrained applications including portable electronics, industrial controls, and automotive subsystems.

FAQ

What is the operating temperature range of the LM20SIBPX at 2.4 V supply?

The LM20SIBPX operates from −30°C to 125°C when powered at 2.4 V. This range expands to −40°C to 125°C at 2.7 V or higher supply voltage. The upper limit remains fixed at 125°C regardless of supply voltage, unlike the LM20B variant which reaches 130°C. This behavior is explicitly defined in Section 6.3 of the SNIS106Q datasheet.

Does the LM20SIBPX require external calibration for accurate temperature measurement?

No, the LM20SIBPX does not require external calibration beyond initial two-point characterization. Its parabolic transfer function VO = (−3.88×10⁻⁶×T²) + (−1.15×10⁻²×T) + 1.8639 V is factory-characterized and guaranteed. Using this equation in host firmware yields ±1.5°C accuracy at 30°C without trimming resistors or EEPROM storage.

Can the LM20SIBPX be used with a 12-bit ADC without an op-amp buffer?

Yes, the LM20SIBPX can drive a 12-bit ADC directly. Its maximum output impedance is 160 Ω, and typical ADC input impedances exceed 10 kΩ, resulting in <0.1% gain error. The datasheet confirms stable operation with capacitive loads ≤300 pF, making direct connection viable for short PCB traces and standard SAR ADCs.

How does light exposure affect the LM20SIBPX output?

The LM20SIBPX in DSBGA package exhibits light sensitivity: bright sunlight may cause up to 1.5 V output drop, while fluorescent office lighting induces <1 mV error. TI recommends mounting the LM20SIBPX inside an opaque enclosure. No permanent damage occurs, and output fully recovers upon light removal - a behavior confirmed in Section 8.1.2 of the datasheet.

What is the shutdown current of the LM20SIBPX and how is it activated?

The LM20SIBPX draws only 0.02 µA when V+ ≤ 0.8 V, enabling true shutdown. This state is activated by pulling the V+ pin below 0.8 V - for example, via GPIO-controlled NMOS switch or logic gate output. Unlike many sensors, no dedicated EN pin is required; shutdown is intrinsic to its ultra-low-quiescent-current architecture.