NXP Semiconductors MMA7361LT

Overview

MMA7361LT from Freescale Semiconductor is a 3-axis capacitive MEMS accelerometer with integrated signal conditioning, selectable ±1.5g/±6g ranges, 0g-detect for freefall protection, self-test capability, and ultra-low-power sleep mode (3 μA). It delivers ratiometric analog outputs (XOUT/YOUT/ZOUT), operates from 2.2–3.6 V, and is factory calibrated for zero-g offset and sensitivity - used in laptop HDD protection, motion-enabled cell phones, and pedometers.

For engineers reviewing the MMA7361LT datasheet, MMA7361LT pinout, MMA7361LT application, or MMA7361LT equivalent, key selection criteria include g-range switching via g-Select pin, 0g-Detect logic output timing, Sleep Mode enable response time (0.5 ms), and analog output impedance (32 kΩ internal + external RC filtering).

Technical Context

The MMA7361LT integrates a surface-micromachined polysilicon g-cell sensor with an ASIC using switched-capacitor measurement, temperature-compensated gain/offset trimming, and a single-pole switched-capacitor low-pass filter. Its ratiometric analog outputs scale linearly with VDD, enabling direct interface to microcontroller ADCs without supply-voltage error compensation.

It features dedicated digital control pins: Sleep (active-low), g-Select (sensitivity mode), Self Test (electrostatic actuation trigger), and 0g-Detect (open-drain logic-high output when all axes read near 0g). The internal 11 kHz sampling clock drives both sensing and filtering, requiring external A/D sampling rates to avoid aliasing.

Key Specifications

Pinout & Package

Package: 3 mm × 5 mm × 1.0 mm LGA-14 (Case 1977-01), bottom-terminal land grid array with exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-axis analog-output accelerometer applications.

Compared with ADXL335 and KXSC7-2050, the MMA7361LT uniquely combines analog output simplicity, dedicated 0g-Detect hardware interrupt, and sub-μA sleep current - making it the most efficient solution for cost-sensitive, battery-powered freefall and motion UI applications requiring minimal firmware overhead.

Availability

MMA7361LT is available at Aetrix Electronics and suitable for laptop anti-theft systems, portable media player drop protection, and smartphone motion-sensing interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for MMA7361LT 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) is a fabless semiconductor company specializing in embedded processing, sensors, and connectivity solutions for automotive, industrial, and consumer markets.

The MMA7361LT belongs to Freescale's MEMS accelerometer product line, designed specifically for ultra-low-power, cost-sensitive motion-sensing applications in handheld electronics - emphasizing factory calibration, integrated logic features, and simplified analog interface.

FAQ

What is the supply voltage range for the MMA7361LT?

The MMA7361LT operates from 2.2 V to 3.6 V. Operation outside this range is not guaranteed, and exceeding 3.6 V may cause permanent damage. Within this window, all specifications - including sensitivity, offset, and noise - are validated. The device's ratiometric output ensures analog performance scales linearly with VDD, simplifying integration with 3.3 V microcontrollers and ADCs.

How does the g-Select pin configure the MMA7361LT sensitivity?

The g-Select pin (Pin 10) sets the full-scale range: logic low selects ±1.5g (800 mV/g), logic high selects ±6g (206 mV/g). An internal pull-down resistor defaults the pin to low, so no external connection is needed for ±1.5g operation. This hardware-selectable range allows a single MMA7361LT design to serve both high-resolution motion UI and robust drop-detection applications without firmware reconfiguration.

What is the function of the 0g-Detect pin on the MMA7361LT?

The 0g-Detect pin (Pin 9) is an open-drain digital output that asserts logic high when the absolute acceleration on all three axes falls below ±0.4 g - indicating linear freefall. It connects directly to a microcontroller interrupt pin, enabling immediate hardware-triggered response (e.g., HDD head parking) without software polling. No external pull-up is mandatory but recommended for reliable logic-level definition.

Can the MMA7361LT be used without external filtering components?

No - external filtering is required for reliable operation. A 0.1 μF capacitor must be placed between VDD and VSS for power supply decoupling. Each analog output (XOUT/YOUT/ZOUT) requires a 3.3 nF capacitor to ground to suppress switched-capacitor clock noise (centered at ~11 kHz). Omitting these capacitors results in significant output ripple and measurement inaccuracy, as confirmed in Freescale's AN3447 and AN3484 application notes.

What is the typical current consumption of the MMA7361LT in Sleep Mode?

The MMA7361LT draws 3 μA typical current in Sleep Mode, achieved by pulling the Sleep pin (Pin 7) low. In this state, analog outputs are disabled and internal circuitry enters ultra-low-power standby. This current drops further if g-Select is held low (±1.5g mode), as gain circuitry consumes less bias current. Total system sleep current depends on proper PCB layout and absence of leakage paths on unused pins.