NXP Semiconductors FXLN8371QR1

Overview

FXLN8371QR1 from NXP (formerly Freescale) is a 3-axis analog-output accelerometer with ±2 g / ±8 g full-scale range selection, high-bandwidth output (2.7 kHz XY / 600 Hz Z), and ultra-low active current of 180 µA. It delivers internally compensated analog outputs (XOUT/YOUT/ZOUT) referenced to a fixed 0.75 V zero-g offset, operating from 1.71–3.6 V supply across –40 °C to +105 °C - used in white goods tilt detection and robotics motion sensing.

For engineers reviewing the FXLN8371QR1 datasheet, FXLN8371QR1 pinout, FXLN8371QR1 application, or FXLN8371QR1 equivalent, key selection criteria include its analog bandwidth configuration, g-range select logic, self-test capability, shutdown current (30 nA), and QFN-12 package compatibility with PCB layout constraints for shock-sensitive applications.

Technical Context

The FXLN8371QR1 integrates a MEMS acceleration sensor with a CMOS ASIC for signal conditioning, featuring independent analog output buffering per axis and factory-configured high-bandwidth mode. Its internal voltage regulator supplies a stable 1.5 V (±0.05 V) to the BYP pin, supporting external decoupling with 70–500 nF capacitors.

Full-scale range is selected via the g-Select pin: logic low enables ±8 g mode (sensitivity 57.25 mV/g), logic high enables ±2 g mode (229 mV/g). Self-test activation (ST pin high) applies electrostatic actuation to verify sensor and signal path integrity without mechanical stimulus.

Key Specifications

Pinout & Package

FXLN8371QR1 uses a 3 mm × 3 mm × 1 mm, 12-pin QFN package (Case 2300-01, 0.65 mm pitch) with exposed pad (EP) not to be soldered. Pin 1 is marked by dot; pins 11 and 12 are NC and may float or connect to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FXLN8361QR1, FXLN8371QR1 trades lower noise for higher XY bandwidth - critical for vibration analysis - while both share identical g-select logic and shutdown behavior. Against ADXL326BCPZ, FXLN8371QR1 offers wider supply range, integrated self-test, and selectable full-scale, but requires different external capacitor values for bandwidth tuning.

Availability

FXLN8371QR1 is available at Aetrix Electronics and suitable for white goods tilt detection, robotics motion feedback, and industrial inclinometer applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant QFN packaging.

Supply support for FXLN8371QR1 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

NXP Semiconductors acquired Freescale in 2015 and continues development of the Xtrinsic sensor portfolio, focusing on intelligent, low-power MEMS solutions for industrial and consumer applications.

The FXLN83xxQ series was designed specifically for cost-sensitive, battery-operated motion sensing in harsh environments - emphasizing analog output simplicity, shock survivability, and factory-configurable bandwidth without digital interfaces.

FAQ

What is the function of the BYP pin on the FXLN8371QR1?

The BYP pin on the FXLN8371QR1 provides the regulated 1.5 V output (±0.05 V) from the internal voltage regulator. It must be decoupled with a 70–500 nF capacitor to stabilize the analog signal chain. This pin supplies bias to internal circuitry and cannot be left floating; improper BYP capacitor selection causes output instability or increased noise in the FXLN8371QR1 analog outputs.

How does the g-Select pin configure full-scale range on the FXLN8371QR1?

On the FXLN8371QR1, the g-Select pin sets the full-scale range: logic high selects ±2 g (229 mV/g sensitivity), logic low selects ±8 g (57.25 mV/g). The transition delay is 340 µs, and the setting persists until changed. This dual-range capability allows one FXLN8371QR1 design to serve both precision tilt and high-g shock detection without hardware modification.

Can the FXLN8371QR1 operate from a 1.8 V supply?

Yes, the FXLN8371QR1 operates from 1.71 V to 3.6 V, making 1.8 V fully supported. At 1.8 V, the logic thresholds remain valid (VIH ≥ 1.35 V, VIL ≤ 0.54 V), and analog performance - including zero-g offset (0.75 V) and noise density - is maintained per characterization data. System designers can directly interface the FXLN8371QR1 with 1.8 V MCUs without level shifters.

What is the purpose of the ST (Self-Test) pin on the FXLN8371QR1?

The ST pin on the FXLN8371QR1 activates an electrostatic self-test that verifies sensor element integrity and analog signal path functionality without mechanical stimulation. When driven high, it induces a known acceleration-like response (35 mg on X/Y, 300 mg on Z), allowing firmware to validate sensor health at startup or during maintenance - a critical feature for safety-critical FXLN8371QR1 deployments.

Is the FXLN8371QR1 pin-compatible with FXLN8361QR1?

Yes, the FXLN8371QR1 is pin-compatible with FXLN8361QR1: identical 12-pin QFN-3×3 mm package, matching pin functions (VDD, GND, XOUT/YOUT/ZOUT, EN, ST, g-Select, BYP), and shared footprint. The only functional difference is factory-configured bandwidth - FXLN8371QR1 uses high-bandwidth mode (2.7 kHz XY), while FXLN8361QR1 uses low-bandwidth mode (1.1 kHz XY) - requiring no PCB changes for substitution.