NXP Semiconductors MMA6231Q

Overview

MMA6231Q from Freescale Semiconductor is a ±10g dual-axis surface-micromachined capacitive accelerometer with integrated signal conditioning, 300 Hz bandwidth, 1.2 mA supply current, and ratiometric analog outputs for X and Y axes. It delivers 0.7 mVrms noise (0.1 Hz–1 kHz) and supports self-test verification in pedometers, impact monitoring, and motion-sensing systems.

For engineers reviewing the MMA6231Q datasheet, MMA6231Q pinout, MMA6231Q application, or MMA6231Q equivalent, key selection criteria include its factory-trimmed 300 Hz low-pass filter, QFN-16 package with defined ST/XOUT/YOUT/VDD/VSS terminals, ±2000 g shock survivability, and ratiometric output scaling critical for microcontroller ADC interfacing.

Technical Context

The MMA6231Q integrates a polysilicon g-cell sensor with an ASIC using switched-capacitor measurement, temperature compensation, and a single-pole low-pass filter-no external components required. Its self-test function applies electrostatic force via a dedicated ST pin to deflect the movable plate, verifying mechanical and electrical integrity.

Output is ratiometric: zero-g offset (1.65 V at VDD = 3.3 V) and sensitivity (120 mV/g typ.) scale linearly with supply voltage. The device operates from 2.7 V to 3.6 V across –20°C to +85°C, with transverse sensitivity limited to ±5% FSO and nonlinearity within ±1.0% FSO.

Key Specifications

Pinout & Package

Package: 16-lead QFN (Case 1477-02), 6 mm × 6 mm × 1.98 mm, exposed thermal flag connected to VSS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMA6231Q, MMA6233Q trades lower power and noise for higher bandwidth, while ADXL322 offers superior noise performance and bandwidth at the cost of added external components and no built-in self-test-making MMA6231Q optimal for cost-sensitive, self-verifying consumer motion systems.

Availability

MMA6231Q is available at Aetrix Electronics and suitable for pedometer systems, appliance control interfaces, and impact monitoring solutions requiring stable component supply, long-term lifecycle support, and consistent factory calibration.

Supply support for MMA6231Q 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

Freescale Semiconductor (now part of NXP Semiconductors) was a leading designer of embedded processors and sensors, specializing in automotive, industrial, and consumer microcontrollers and MEMS devices.

The MMA6200 series-including MMA6231Q-was engineered for cost-effective, self-contained motion sensing in battery-powered portable electronics, emphasizing factory-calibrated analog outputs and robust mechanical reliability.

FAQ

What is the operating voltage range for the MMA6231Q?

The MMA6231Q operates from 2.7 V to 3.6 V. Within this range, it functions as a fully calibrated linear accelerometer; outside this range, linearity and calibration are not guaranteed. At 3.3 V nominal supply, zero-g output is 1.65 V and sensitivity is 120 mV/g, both scaling ratiometrically with VDD. The device draws 1.2 mA typical current under these conditions.

How does the self-test function work on the MMA6231Q?

The MMA6231Q self-test is activated by applying a logic-high signal (>0.7×VDD) to the ST pin (Pin 12). This applies electrostatic force to the movable g-cell plate, producing a calibrated 2.0 g equivalent output on XOUT or YOUT. Response settles within 2.0 ms, and internal fault detection latches errors if EEPROM parity fails-ensuring test validity before deployment.

What is the significance of ratiometric output in the MMA6231Q?

Ratiometric output means both zero-g offset and sensitivity scale linearly with VDD. For example, at 3.0 V supply, zero-g shifts to ~1.5 V and sensitivity drops proportionally. This cancels supply-induced errors when the MMA6231Q shares VDD with a microcontroller's ADC reference, eliminating need for precision voltage references in cost-sensitive designs.

Can the MMA6231Q be used in high-shock environments?

Yes-the MMA6231Q is rated for ±2000 g mechanical shock and survives 1.2 m drops onto concrete. Its surface-micromachined polysilicon g-cell and hermetic wafer-level packaging provide mechanical resilience far exceeding its ±10 g measurement range, making it suitable for handheld tools, industrial equipment, and transportation-mounted sensors.

What package type and footprint does the MMA6231Q use?

The MMA6231Q uses a 16-lead QFN package (Case 1477-02), measuring 6 mm × 6 mm × 1.98 mm with an exposed thermal flag tied to VSS. The recommended footprint includes solder pads sized per Freescale's Issue B drawing, with no traces or vias under the package body to prevent ground shorts and ensure thermal stability.