NXP Semiconductors MMA6811BKWR2

Overview

MMA6811BKWR2 from NXP Semiconductors (formerly Freescale) is a dual-axis SPI inertial sensor designed for automotive airbag deployment systems. It delivers ±60g X-axis and ±25g Y-axis full-scale acceleration measurement, 10-bit signed/unsigned SPI output, and programmable low-pass filtering with 12 selectable cutoff frequencies from 50 Hz to 1000 Hz.

For engineers reviewing the MMA6811BKWR2 datasheet, MMA6811BKWR2 pinout, MMA6811BKWR2 application, or MMA6811BKWR2 equivalent, key selection criteria include AEC-Q100 Grade 1 qualification, independent arming outputs per axis, offset cancellation with <0.25 LSB/s slew rate, and over-damped lateral g-cell architecture for crash pulse fidelity.

Technical Context

The MMA6811BKWR2 integrates two over-damped lateral MEMS sensing elements with independent signal chains, each featuring ΣΔ ADCs, SINC filters, and configurable IIR low-pass filters. Its internal 8 MHz oscillator feeds a programmable clock divider to support 12 discrete LPF configurations across two timing groups (ts = 8 μs and 16 μs).

Digital functionality includes independent ARM_X/ARM_Y open-drain arming outputs configurable via DEVCFG register, self-test magnitude selection (low/high), and CRC-protected OTP and register arrays. The device implements voltage monitoring on VCC, VREG, and VREGA rails with hysteresis, and supports both 3.3 V and 5 V single-supply operation.

Key Specifications

Pinout & Package

Pb-free 16-pin QFN package, 6 mm × 6 mm, exposed thermal pad (Case 2086-01), with analog/digital ground separation and dedicated regulator pins for noise isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMA6813BKWR2, the MMA6811BKWR2 offers higher X-axis range for frontal crash detection but reduced Y-axis margin; versus ADXL362ACPZ-RL7, it provides certified automotive reliability and crash-specific signal chain optimization at the cost of higher current draw and fixed dual-axis orientation.

Availability

MMA6811BKWR2 is available at Aetrix Electronics and suitable for automotive airbag control units, rollover detection modules, and pre-crash system designs requiring stable component supply, AEC-Q100 compliance, and production-grade traceability.

Supply support for MMA6811BKWR2 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 is a global semiconductor company specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The MMA68xx family was developed specifically for automotive safety systems, with emphasis on crash pulse fidelity, functional safety readiness, and robustness under extreme mechanical and thermal stress.

FAQ

What is the full-scale acceleration range specification for MMA6811BKWR2?

The MMA6811BKWR2 has an X-axis full-scale range of ±60g and a Y-axis full-scale range of ±25g, as specified in the ordering information table of the Freescale MMA68xx datasheet Rev. 5. These ranges are factory-set and cannot be reconfigured in-system. The MMA6811BKWR2 uses independent digital sensitivity values: 8.192 LSB/g on X and 20.479 LSB/g on Y, enabling optimal resolution for asymmetric crash event profiles.

Does MMA6811BKWR2 support both 3.3 V and 5 V supply voltages?

Yes, the MMA6811BKWR2 supports single-supply operation from 3.135 V to 5.25 V, covering standard 3.3 V and 5 V automotive domains. Internal regulators generate stable 2.5 V supplies for analog (VREGA) and digital (VREG) circuitry. Power supply monitors verify VCC ≥ 2.74 V (falling), VREG ≥ 2.10 V (falling), and VREGA ≥ 2.20 V (falling) to ensure reliable operation across voltage transients.

How is the pin configuration of MMA6811BKWR2 validated for automotive use?

The MMA6811BKWR2 uses a 16-pin QFN package (6 mm × 6 mm, Case 2086-01) with physically separated analog/digital grounds (VSSA/VSS), dedicated regulator inputs (VREGA/VREG), and open-drain arming outputs (ARM_X/ARM_Y) that meet automotive load-switching requirements. Pin functions are fully documented in Table 2 of the MMA68xx datasheet, including mandatory tie-down of TEST/VPP to VSS and decoupling capacitor placement per Figure 1.

What AEC-Q100 qualification level does MMA6811BKWR2 meet?

The MMA6811BKWR2 is qualified to AEC-Q100 Revision G (May 14, 2007) for Grade 1 operation (−40°C to +105°C ambient), as stated in the referenced documents section of the MMA68xx datasheet. This includes stress testing for temperature cycling, humidity bias, high-temperature operating life, and electrostatic discharge (HBM ±2000 V, CDM ±750 V), confirming suitability for passenger compartment airbag control units.

Can MMA6811BKWR2 perform self-test and offset monitoring?

Yes, the MMA6811BKWR2 supports calibrated self-test with two deflection magnitudes (ΔSTLow ≈ 10.68 g, ΔSTHI ≈ 21.37 g) selectable per axis via STMAG_X/STMAG_Y bits. It also includes an offset monitor with programmable thresholds (OFFTHRPOS = 612 LSB, OFFTHRNEG = 412 LSB) and optional offset cancellation using >6 s averaging and <0.25 LSB/s slew rate-features critical for long-term zero-g stability in automotive deployments.