STMicroelectronics LPS33KTR

Overview

LPS33KTR from STMicroelectronics is a MEMS-based digital barometric pressure sensor with potted gel packaging, delivering 24-bit absolute pressure output (300–1200 hPa) and 16-bit temperature output over I²C. It operates from 1.7–3.6 V, consumes as low as 4 µA in low-current mode, and features ±0.5 hPa relative accuracy at 25 °C-enabling precise altitude tracking in wearable fitness trackers.

For engineers reviewing the LPS33KTR datasheet, LPS33KTR pinout, LPS33KTR application, or LPS33KTR equivalent, key selection criteria include its 0.008 hPa RMS noise in low-noise mode, 20× overpressure tolerance (up to 24,000 hPa), factory-trimmed calibration stored in non-volatile memory, and CCLGA-4L ceramic package with metal lid for harsh-environment resilience.

Technical Context

The LPS33KTR integrates a piezoresistive Wheatstone bridge sensing element fabricated via ST's proprietary silicon membrane process, coupled with a low-noise analog front end, 24-bit ADC, and embedded digital signal processor for real-time temperature compensation. Its measurement chain outputs calibrated pressure and temperature data directly via I²C without host-side calibration.

It supports programmable output data rates from 1 Hz to 75 Hz in both pressure and temperature channels, with optional low-pass filtering (ODR/9 or ODR/20) and block-data-update (BDU) mode to prevent read tearing across 3-byte pressure registers (PRESS_OUT_XL/L/H). The device uses a fixed 7-bit slave address (1011101b) and complies with I²C fast mode (400 kHz).

Key Specifications

Pinout & Package

The LPS33KTR is housed in a 3.3 × 3.3 × 2.9 mm ceramic cavity LGA (CCLGA-4L) package with metal lid and integrated potting gel for environmental sealing. The package includes a pressure port enabling external ambient pressure access to the MEMS die.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar barometric pressure sensor applications.

Compared with BMP388 and MS5637-02BA03, the LPS33KTR uniquely combines gel-based environmental hardening, on-device temperature compensation, and atomic register read control-making it optimal for sealed, maintenance-free deployments in wearables and industrial edge nodes where reliability trumps minimal footprint.

Availability

LPS33KTR is available at Aetrix Electronics and suitable for wearable devices, portable altimeters, and weather station equipment requiring stable component supply across multi-year production cycles.

Supply support for LPS33KTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing MEMS sensors, microcontrollers, power ICs, and automotive-grade components since 1987.

The LPS33KTR belongs to ST's high-reliability MEMS pressure sensor family, engineered specifically for compact, battery-operated devices needing certified long-term stability and resistance to chemical, thermal, and mechanical stress.

FAQ

What is the pressure port configuration and how is it implemented in the CCLGA-4L package?

The LPS33KTR uses a bottom-port design: the ceramic substrate contains a dedicated aperture aligned beneath the MEMS die, allowing ambient pressure to reach the sensing membrane through the package underside. This port is sealed only by the metal lid's gasket interface-not by epoxy-ensuring accurate static pressure coupling while maintaining IP54-equivalent ingress protection via the potting gel's barrier properties.

How does the factory calibration data persist and get applied during operation?

Trimming coefficients for pressure and temperature compensation are laser-trimmed during final test and stored in on-chip non-volatile memory. At power-on, the BOOT bit triggers automatic loading of these values into active calibration registers. No host intervention is required-the DSP applies them transparently to raw ADC outputs before I²C readout, ensuring consistent accuracy across voltage, temperature, and unit-to-unit variation.

Can the LPS33KTR operate reliably in high-humidity or chemically aggressive environments?

Yes-the potted gel (ASTM D1403 hardness 70, permeability 7 g/m²·24 hr) fully encapsulates the die and wire bonds, providing proven resistance to chlorine, bromine, commercial detergents, fuels, and solvents. Combined with the hermetic metal-lid seal and −40 °C to +85 °C operational range, it meets IPC-J-STD-020 moisture sensitivity level 3 for reflow and long-term field reliability in humid or corrosive settings.

What I²C timing constraints must be observed for reliable communication at 400 kHz?

At 400 kHz fast mode, SCL clock low time must be ≥1.3 µs and high time ≥0.6 µs; SDA setup time must be ≥100 ns and hold time ≥0.9 µs. Pull-up resistors should be sized to meet rise-time specs (≤300 ns) with bus capacitance ≤400 pF. The device tolerates 0.2×VDD and 0.8×VDD switching thresholds, but improper slew rate or excessive capacitance causes NACK or data corruption-verified per Table 5 in DS12817 Rev 3.