Freescale Semiconductor
Technical Data
MMA81XXTKEG
Rev 0, 12/2009
Digital X-Axis or Z-Axis
Accelerometer
The MMA81XXTKEG (Z-axis) and MMA82XXTKEG (X-axis) are members of
Freescale’s family of DSI 2.0-compatible accelerometers. These devices
incorporate digital signal processing for filtering, trim and data formatting.
Features
•
Available in 20g, 40g, 50g, 100g, 150g, and 250g (MMA82XXTKEG, X-axis)
and 40g, 100g, 150g, and 250g (MMA81XXTKEG, Z-axis). Additional
g-ranges may be available upon request
80 customer-accessible OTP bits
10-bit digital data output from 8 to 10 bit DSI output
6.3 to 30 V supply voltage
On-chip voltage regulator
Internal self-test
Minimal external component requirements
RoHS compliant (-40 to +125ºC) 16-pin SOIC package
DSI 2.0 Compliant
Z-axis transducer is overdamped
Qualified AEC-Q100, Rev. F Grade 2 (-40°C/ +105°C)
MMA81XXTKEG
MMA82XXTKEG
SERIES
SINGLE-AXIS
DSI 2.0
ACCELEROMETER
•
•
•
•
•
•
•
•
•
•
TKEG SUFFIX (Pb-free)
16-LEAD SOIC
CASE 475-01
PIN CONNECTIONS
Typical Applications
•
•
•
Crash detection (Airbag)
Impact and vibration monitoring
Shock detection.
N/C
N/C
C
REG
V
PP
/TEST
C
FIL
D
OUT
V
GND
/D
IN
CLK
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
SS
V
SS
BUSRTN
BUSIN
BUSOUT
H
CAP
V
SS
C
REG
16-PIN SOIC PACKAGE
© Freescale Semiconductor, Inc., 2009. All rights reserved.
ORDERING INFORMATION
Device Name
MMA8225EGR2
MMA8225EG
MMA8225TKEGR2*
MMA8225TKEG*
MMA8215EGR2
MMA8215EG
MMA8210TEGR2
MMA8210TEG
MMA8210TKEGR2*
MMA8210TKEG*
MMA8205TEGR2
MMA8205TEG
MMA8205TKEGR2*
MMA8205TKEG*
MMA8204EGR2
MMA8204EG
MMA8204TKEGR2*
MMA8204TKEG*
MMA8202EGR2
MMA8202EG
MMA8125EGR2
MMA8125EG
MMA8125TKEGR2*
MMA8125TKEG*
MMA8115EGR2
MMA8115EG
MMA8110EGR2
MMA8110EG
MMA8110TKEGR2*
MMA8110TKEG*
MMA8104EGR2
MMA8104EG
MMA8104TKEGR2*
MMA8104TKEG*
X-axis g-Level
250
250
250
250
150
150
100
100
100
100
50
50
50
50
40
40
40
40
20
20
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Z-axis g-Level
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
250
250
250
250
150
150
100
100
100
100
40
40
40
40
Temperature Range
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
-40 to +125°C
SOIC 16 Package
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
475-01
Packaging
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
Tape & Reel
Tubes
*Part number sourced from a different facility.
MMA81XXTKEG
2
Sensors
Freescale Semiconductor
SECTION 1 GENERAL DESCRIPTION
MMA81XXTKEG/MMA82XXTKEG family is a satellite accelerometer which is comprised of a single axis, variable capacitance
sensing element with a single channel interface IC. The interface IC converts the analog signal to a digital format which is trans-
mitted in accordance with the DSI-2.0 specification.
1.1
OVERVIEW
Signal conditioning begins with a Capacitance to Voltage conversion (C to V) followed by a 2-stage switched capacitor amplifier.
This amplifier has adjustable offset and gain trimming and is followed by a low-pass switched capacitor filter with Bessel function.
Offset and gain of the interface IC are trimmed during the manufacturing process. Following the filter the signal passes to the
output stage. The output stage sensitivity incorporates temperature compensation.
The output of the accelerometer signal conditioning is converted to a digital signal by an A/D converter. After this conversion the
resultant digital word is converted to a serial data stream which may be transmitted via the DSI bus. Power for the device is
derived from voltage applied to the BUSIN/BUSOUT and V
SS
pins. Bus voltage is rectified and applied to an external capacitor
connected to the H
CAP
pin. During data transmissions, the device operates from stored charge on the external capacitor. An
integrated regulator supplies fixed voltage to internal circuitry.
A self-test voltage may be applied to the electrostatic deflection plate in the sensing element. Self-Test voltage is factory trimmed.
Other support circuits include a bandgap voltage reference for the bias sources and the self-test voltage.
A total of 128 bits of One-Time Programmable (OTP) memory, are provided for storage of factory trim data, serial number and
device characteristics. Eighty OTP bits are available for customer programming. These eighty OTP bits may be programmed via
the DSI Bus or through the serial test/trim interface. OTP integrity is verified through continuous parity checking. Separate parity
bits are provided for factory and customer programmed data. In the event that a parity fault is detected, the reserved value of
zero is transmitted in response to a Read Acceleration Data command.
A block diagram illustrating the major elements of the device is shown in
Figure 1-1.
MMA81XXTKEG
Sensors
Freescale Semiconductor
3
REGULATOR
TRIM
11
VOLTAGE
REGULATOR
INTERNAL
SUPPLY
VOLTAGE
9
H
CAP
C
REG
3
12
C
REG
BUSOUT
BUSIN
13
N/C
N/C
1
2
V
SS
V
SS
V
SS
BUSRTN
BANDGAP
REFERENCE
16
15
10
14
GROUND
LOSS
DETECTOR
7
V
GND
/D
IN
OSCILLATOR
SELFTEST
TRIM
OSC
TRIM
SELFTEST
VOLTAGE
LOGIC
COMMAND DECODE
STATE MACHINE
RESPONSE GENERATION
4
OTP
PROGRAMMING
INTERFACE
6
8
V
PP
/TEST
D
OUT
CLK
SELF-TEST ENABLE
A-TO-D
CONVERTER
SWITCHES SHOWN
IN NORMAL OPERATING
CONFIGURATION
g-CELL
C-TO-V
CONVERTER
LOW-PASS
FILTER
5
C
FIL
GAIN
TRIM
OFFSET
TRIM
TCS
TRIM
Figure 1-1. Overall Block Diagram
MMA81XXTKEG
4
Sensors
Freescale Semiconductor
1.2
PACKAGE PINOUT
The pinout for this 16-pin device is shown in
Figure 1-2.
+Z
N/C
N/C
C
REG
V
PP
/TEST
C
FIL
D
OUT
V
GND
/D
IN
CLK
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
SS
V
SS
BUSRTN
BUSIN
BUSOUT
H
CAP
V
SS
C
REG
+X
-X
-Z
ACTIVATION OF Z-AXIS SELF-TEST
CAUSES OUTPUT TO
BECOME MORE POSITIVE
PROJECTION
16-PIN SOIC PACKAGE
ACTIVIATION OF X-AXIS SELF-TEST
CAUSES OUTPUT TO
BECOME MORE POSITIVE
CASE: 475-01
N/C: NO INTERNAL CONNECTION
Output response to displacement in the direction of arrows.
+1 g
+1 g
0g
0g
0g
0g
-1 g
TO CENTER OF
GRAVITATIONAL FIELD
-1 g
Response to static orientation within 1 g field.
Figure 1-2. Device Pinout
MMA81XXTKEG
Sensors
Freescale Semiconductor
5