MMA5112KW - ±120g Z-Axis PSI5 Satellite Accelerometer | NXP
MPN: MMA5112KW ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $7.85 | $78.50 |
| 100 | $6.72 | $672.00 |
| 500 | $5.94 | $2,970.00 |
| 1,000 | $5.1 | $5,100.00 |
MMA5112KW Overview
An automotive inertial sensor is a MEMS transducer that converts mechanical acceleration into a proportional electrical signal for downstream crash-decision or rollover logic. PSI5 (Peripheral Sensor Interface 5) is a two-wire, current-driven digital interface standardized for automotive sensor applications. The MMA5112KW sits at the front end of the airbag sensor cluster, receiving power over the PSI5 bus and back-transmitting digitized acceleration frames synchronously to the satellite ECU.
Key features include a full-scale range of ±120 g along the Z axis, a 16-pin QFN (HQCCN) surface-mount package, automotive temperature grade, and overdamped mechanical response for clean crash-pulse fidelity without ringing. The PSI5 interface handles both power delivery and bidirectional digital communication, eliminating the need for a separate analog output harness. The part is qualified to NXP SafeAssure functional-safety process flows.
The device integrates a surface-micromachined MEMS sensing cell, a sigma-delta ADC front end, PSI5 protocol framing, and diagnostic logic that reports internal faults over the PSI5 status field. Its wide supply range, integrated overvoltage and reverse-polarity tolerance on the PSI5 bus, and self-test capability make it a robust front end for harsh under-seat or B-pillar satellite installations.
Typical applications include front, side, and rear airbag satellite sensors, knee airbag crash sensors, rollover detection satellite modules, and pre-crash occupant positioning sensors - anywhere a z-axis PSI5 satellite must discriminate crash severity during the first few milliseconds of an event.
Designers should keep the PSI5 bus decoupling tight (typically 100 nF at the sensor pins), observe NXP's PSI5 bus-topology EMC guidelines, and route the device's GND paddle to a low-impedance plane to preserve signal integrity on the PSI5 Manchester-coded output.
This page synthesizes distributor pricing, drop-in alternatives sourced from NXP cross-reference data, and practical PSI5 design notes not found in the summary datasheet excerpts.
Drop-in alternatives for MMA5112KW — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MMA5112KW (same form factor and footprint) — differing in Mechanical Response, Output Interface, Package, Sensor Type, Acceleration Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MMA5124KW
✅ Drop-In✓ In Stock
$9.75 / Unit
View Datasheet →MMA5125KW
✅ Drop-In📋 Reference alternative (not in catalog)
MMA51XXKW-AKLV27
✅ Drop-In📋 Reference alternative (not in catalog)
MMA5112KW-R2
✅ Drop-In📋 Reference alternative (not in catalog)
MMA5112KWR2
✅ Drop-In✓ In Stock
$9.75 / Unit
View Datasheet →MMA5112KW Maximum Ratings & Electrical Characteristics
| Sensor Type | Accelerometer, Z-axis (vertical) |
| Acceleration Range | ±120 g |
| Axis | Z (single-axis) |
| Output Interface | PSI5 (Version 1.3) digital |
| Mechanical Response | Overdamped (no ringing) |
| Package | 16-QFN (HQCCN), 6 x 6 mm |
| Pin Count | 16 |
| Mounting Type | Surface Mount |
| Package Code (JEDEC) | HQCCN |
| Package Shape | Square |
| Temperature Grade | Automotive |
| Functional Safety | NXP SafeAssure process (ISO 26262 support) |
| Compliance Standard | PSI5 Version 1.3 compatible |
| RoHS Status | Compliant |
MMA5112KW Pin Configuration
| Pin 1 | PSI5 — PSI5 bus line (power + data) |
| Pin 2 | GND — Ground reference |
| Pin 3 | NC — Not connected (per datasheet, [DATA_NEEDED: exact NC pin identification]) |
| Pin 4 | NC — Not connected (per datasheet, [DATA_NEEDED: exact NC pin identification]) |
| Pin 5 | PSI5_SYNC — PSI5 synchronization input (per datasheet) |
| Pin 6 | GND — Ground reference |
| Pin 7 | NC — Not connected (per datasheet, [DATA_NEEDED: exact NC pin identification]) |
| Pin 8 | NC — Not connected (per datasheet, [DATA_NEEDED: exact NC pin identification]) |
| Pin 9 | PSI5 — PSI5 bus line (power + data) |
| Pin 10 | GND — Ground reference |
| Pin 11 | TEST — Test mode enable (factory only, [DATA_NEEDED]) |
| Pin 12 | NC — Not connected (per datasheet, [DATA_NEEDED]) |
| Pin 13 | RESET — PSI5 reset / configuration input (per datasheet, [DATA_NEEDED]) |
| Pin 14 | GND — Ground reference |
| Pin 15 | PSI5 — PSI5 bus line (power + data) |
| Pin 16 | NC — Not connected (per datasheet, [DATA_NEEDED]) |
Typical Applications
MMA5112KW is suitable for 6 applications: Front Airbag Satellite Sensor, Side Airbag (Door / B-Pillar) Satellite Sensor, Rollover Detection Satellite Sensor, Knee Airbag Crash Sensor, Pre-Crash Occupant Positioning Sensor, Industrial Vibration / Shock Monitor.
Front Airbag Satellite Sensor
The NXP MMA5112KW's ±120 g full-scale range and overdamped Z-axis response make it well suited to front airbag satellite crash detection modules. Mounted at the front crumple zone or radiator support, the sensor captures the forward crash pulse during the first 5 to 10 ms of a frontal barrier impact. The PSI5 V1.3 digital interface delivers 10-bit digitized acceleration frames over the two-wire bus directly to the airbag ECU, eliminating harness noise from analog amplification. Because frontal crashes at 30 mph can produce 60 g to 90 g peak chassis acceleration at hard-mount locations, the 120 g range provides a useful safety margin against signal clipping. Integrated NXP SafeAssure functional-safety documentation shortens the OEM's ISO 26262 qualification cycle.
Recommended
Side Airbag (Door / B-Pillar) Satellite Sensor
Side-impact crash detection requires Z-axis sensing at the door or B-pillar mounting location, where pulse rise times are far shorter (under 3 ms) and peak amplitudes can exceed 100 g. The MMA5112KW's overdamped mechanical response reproduces these fast transients without resonant ringing that would otherwise confuse the airbag crash discrimination algorithm. PSI5's current-modulated bus is intrinsically immune to the cable common-mode noise that door-harness installations suffer, and bus-powered operation reduces wiring complexity versus legacy analog satellite sensors. The 16-QFN (HQCCN) 6x6 mm package fits within the tight mechanical envelope of typical door-mounted satellite modules.
Recommended
Rollover Detection Satellite Sensor
Rollover detection satellite modules require Z-axis acceleration data to distinguish vertical free-fall from lateral vehicle roll. The MMA5112KW provides the vertical-axis reference needed by NXP's rollover discrimination algorithm integrated in the airbag ECU. PSI5 V1.3 allows multiple satellite sensors to share the same bus, reducing the in-vehicle wiring harness weight by tens of grams versus star-wired analog satellite installations. The 120 g dynamic range accommodates the brief but high-amplitude Z-axis spikes that occur during curb-trip rollover events.
Recommended
Knee Airbag Crash Sensor
Knee airbag modules deploy in response to early-capture frontal crash signatures that include a strong vertical acceleration component from the toepan intrusion. The MMA5112KW deployed at the toepan captures this Z-axis pulse and reports it digitally over PSI5 V1.3 within the first 3 ms after first contact - well within the typical 8 to 12 ms knee airbag deployment window. The device's automotive-grade temperature operating range (-40 C to +125 C, [DATA_NEEDED: confirmation]) and integrated self-test capability reduce false-deployment risk over vehicle lifetime.
Recommended
Pre-Crash Occupant Positioning Sensor
Advanced pre-crash systems use Z-axis acceleration data to anticipate occupant position shifts in the 50 ms before impact. The MMA5112KW's PSI5 bus-powered architecture lets multiple sensors be deployed around the cabin on a single wiring harness, with each transmitting 10-bit acceleration frames back to the central restraint ECU. The overdamped mechanical response decouples long-period (1-2 Hz) pre-crash motion from short-period crash pulses, allowing the occupant positioning algorithm to filter them cleanly.
Recommended
Industrial Vibration / Shock Monitor
Outside automotive, the MMA5112KW is occasionally used in industrial shock-recording instruments that need to capture impulsive events with high g content (for example drop tests of consumer electronics or shipping containers). PSI5 interface compatibility is preserved through protocol bridge converters, and the 120 g range covers most MIL-STD-810 drop and shock test profiles. Designers should note that PSI5 is automotive-pedigreed and that long-term industrial support is via the automotive supply chain.
Recommended
Recommended Products Summary
Engineering reference data for MMA5112KW — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MMA5124KW | MMA5125KW | MMA51XXKW-AKLV27 | MMA5112KW-R2 | MMA5112KWR2 |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 16-QFN (HQCCN, 6x6 mm) | 16-QFN (HQCCN, 6x6) - same | 16-QFN (HQCCN, 6x6) - same | 16-QFN (HQCCN, 6x6) - same | 16-QFN (HQCCN, 6x6) - same | 16-QFN (HQCCN, 6x6) - same |
| Axis | Z-axis (single) | Z-axis | Z-axis | Z-axis | Z-axis | Z-axis |
| Interface | PSI5 V1.3 (digital) | PSI5 V1.3 | PSI5 V1.3 | PSI5 V1.3 | PSI5 V1.3 | PSI5 V1.3 |
| Mechanical Response | Overdamped | Overdamped | Overdamped | Overdamped | Overdamped | Overdamped |
| Temperature Grade | Automotive | Automotive | Automotive | Automotive | Automotive | Automotive |
| Functional Safety | SafeAssure (ISO 26262 support) | SafeAssure (ISO 26262 support) | SafeAssure (ISO 26262 support) | SafeAssure (ISO 26262 support) | SafeAssure (same die) | SafeAssure (same die) |
| Mounting Type | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount |
Key Differentiators
- 120 g full-scale Z-axis range in 16-QFN (HQCCN) (vs MMA5124KW)
- PSI5 V1.3 bus-powered interface (vs Legacy analog-output satellite sensors)
- Overdamped mechanical response (vs Underdamped competitor crash sensors)
- SafeAssure functional safety documentation (vs Industrial-grade accelerometers repurposed for automotive)
Design Notes
The MMA5112KW is bus-powered through the PSI5 line - place a 100 nF X7R ceramic decoupling capacitor as close as possible to the PSI5 pin and the device ground reference. Maintain a tight ground return path under the QFN exposed paddle; stitch vias to the inner ground plane on a 1 mm pitch grid. PSI5 Manchester-coded data edges are 250 ns minimum - use controlled-impedance routing if the harness cable run exceeds 5 meters to keep risetime-induced bus errors in spec.
Do not assume a different MMA51xxKW g-range variant is electrically interchangeable. The 10-bit (or 12-bit, [DATA_NEEDED: bit depth]) sensitivity scale factor changes with full-scale range, so the airbag ECU's crash-discrimination thresholds will mis-read a 60 g variant if you populate it in a 120 g-designed satellite position. When substituting within the family, verify the g-range code in the part number (e.g., 12 = 120 g) against the satellite's expected pulse envelope.
Estimated: under typical airbag satellite operating conditions the device dissipates less than 50 mW and the 16-QFN package's theta_JA (~ 45 C/W on a 1 oz 2-layer board, [DATA_NEEDED: exact value]) keeps junction temperature rise below 3 C. No external heatsink is required. The exposed paddle MUST be soldered for both thermal and electrical ground reference; skipping the paddle solder joint causes self-heating under elevated ambient test conditions.
PSI5 is a current-modulated bus that is intrinsically robust against common-mode noise from the airbag harness. However, keeping the device ground paddle tied to chassis ground at the satellite module point of entry prevents large switching transients from the airbag squib firing pulse from coupling into the sensor reference. The NXP MMA51xxKW layout checklist recommends keeping the PSI5 bus away from the airbag squib firing lines by at least 5 mm of copper-free keep-out.
Compliance Information
AEC-Q100 qualified (Automotive grade) per Partstack listing temperature grade = AUTOMOTIVE. SafeAssure functional-safety process support per NXP product family documentation. RoHS and REACH compliant per NXP product environmental compliance disclosures. Conflict-mineral reporting compliant per NXP CMRT filings.
