MMA2240KEG Freescale Semiconductor Rev 0, 11/2009 Technical Data Surface Mount Micromachined Accelerometer MMA2240KEG The MMA2240KEG is a silicon capacitive, micromachined accelerometer featuring signal conditioning, a 2-pole low pass filter and temperature compensation. Zero-g offset full scale span and filter cut-off are factory set and require no external devices. A full system self-test capability verifies system functionality. MMA2240KEG: X-AXIS SENSITIVITY MICROMACHINED Features ACCELEROMETER Integral Signal Conditioning 7g Linear Output Ratiometric Performance 2nd Order Bessel Filter Preserves Pulse Shape Integrity Calibrated Self-test Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status Transducer Hermetically Sealed at Wafer Level for Superior Reliability Robust Design, High Shocks Survivability Pb-Free Termination Environmentally Preferred Package Qualified AEC-Q100, Rev. F Grade 2 (-40C/ +105C) KEG SUFFIX (Pb-FREE) Typical Applications 16-LEAD SOIC Vibration Monitoring and Recording CASE 475-01 Dynamic Suspension Control ORDERING INFORMATION Device Name Temperature Range Case No. Package MMA2240EG 40 to 85C 475-01 SOIC-16 MMA2240EGR2 40 to 85C 475-01 SOIC-16, Tape & Reel MMA2240KEG* 40 to 85C 475-01 SOIC-16 MMA2240KEGR2* 40 to 85C 475-01 SOIC-16, Tape & Reel *Part number sourced from a different facility. V DD Temp G-Cell V N/C 16 N/C Integrator Gain Filter 1 OUT Comp Sensor N/C 2 15 N/C N/C 14 N/C 3 ST 4 13 N/C ST Control Logic & V 12 N/C Clock 5 OUT Oscillator Self-test EPROM Trim Circuits Generator 6 11 N/C STATUS V SS 10 N/C V 7 SS 8 9 N/C V DD STATUS Figure 2. Pin Connections Figure 1. Simplified Accelerometer Functional Block Diagram Freescale Semiconductor, Inc., 2009. All rights reserved.The block diagram of the MMA2240EG is shown in The output of the filter is then amplified by the output stage Figure 1. The X-axis g-cell is constructed using surface which also has a temperature compensation circuit for micromachining and the interface IC is fabricated in a sensitivity which can be adjusted using the EPROM trim 1.2 micron (60%) silicon gate CMOS process. register. The signal conditioning of the accelerometer channel An adjustable self-test voltage to be applied to the begins with a capacitance to voltage conversion (C to V) electrostatic deflection plate in the sensing element. Other followed by a 2-stage switched capacitor amplifier. This support circuits include a bandgap voltage reference for the 2-stage amplifier has adjustable offset and gain trimming. bias sources and the self-test voltage. The interface IC also The offset and gain of the interface IC can be controlled by has its own power supply filter which feeds all the analog the serially accessed EPROM trimming register. functions in order to increase the power supply rejection ratio Following the 2-stage amplifier the signal passes through (PSRR). a 2-pole, switched capacitor filter with a Bessel characteristic. Included are several fault checks for low voltage detect The rolloff frequency of the filter is trimmed by adjusting the (LVD), clock and/or bias monitoring, and a check of the stored frequency of the single on-chip oscillator. The frequency is even parity of the EPROM trim register. Failure of any of adjusted by trimming the bias current to the oscillator using these monitoring functions will result in the STATUS the EPROM trim register. input being driven high. Table 1. Maximum Ratings (Maximum ratings are the limits to which the device can be exposed without causing permanent damage.) Rating Symbol Value Unit (1) Unpowered Acceleration (all axes) g 2000 g shock 0.5 ms duration In use g shocks powered or unpowered G < 100 g shock in use Capable of < 5 ppm device failure rate any duration In use g shocks powered or unpowered G < 100 - 1500 g shock in use Capable of < 50 ppm device failure rate 0.6 ms duration Supply Voltage V 0.3 to +7.0 V DD Storage Temperature Range T 40 to +125 C stg This device is sensitive to mechanical shock. Improper handling can cause permanent damage of the part or 1. cause the part to otherwise fail. ELECTRO STATIC DISCHARGE (ESD) WARNING: This device is sensitive to electrostatic discharge. Although the Freescale accelerometers contain internal performance or cause failure of the chip. When handling the 2kV ESD protection circuitry, extra precaution must be taken accelerometer, proper ESD precautions should be followed by the user to protect the chip from ESD. A charge of over to avoid exposing the device to discharges which may be 2000 volts can accumulate on the human body or associated detrimental to its performance. test equipment. A charge of this magnitude can alter the MMA2240KEG Sensors 2 Freescale Semiconductor