PMMA7450LR2 Freescale Semiconductor, Inc, PMMA7450LR2 Datasheet - Page 12

• Manufacturer Part Number: PMMA7450LR2
• Description: ?2g/?4g/?8g Three Axis Low-g Digital Output Accelerometer
• Manufacturer: Freescale Semiconductor, Inc

NOTES:
12
MMA7450L
Table 7. User Register Summary
Address
$0A
$0B
$0C
$0D
$0E
$00
$01
$02
$03
$04
$05
$06
$07
$08
$09
$0F
1. Use 1 ~ 10 μA capacitor on V
2. Physical coupling distance of the accelerometer to
3. Place a ground plane beneath the accelerometer to
power source.
the microcontroller should be minimal.
reduce noise, the ground plane should be attached to
all of the open ended terminals shown in
and
Figure
WHOAMI
DETSRC
STATUS
USRINF
XOUTL
XOUTH
YOUTL
YOUTH
ZOUTH
XOUT8
YOUT8
ZOUTL
ZOUT8
Name
I2CAD
TOUT
16.
“Temperature output value” (Optional)
“Who am I” value (Optional)
10 bits output value X MSB
10 bits output value Y MSB
10 bits output value Z MSB
User information (Optional)
10 bits output value X LSB
10 bits output value Y LSB
10 bits output value Z LSB
Detection source registers
8 bits output value X
8 bits output value Y
8 bits output value Z
I2C device address
100uF
Status registers
Definition
(Reserved)
DD
to decouple the
Figure 16. SPI Connection to MCU
100uF
Figure 15
XOUT[7]
YOUT[7]
ZOUT[7]
XOUT[7]
YOUT[7]
ZOUT[7]
TMP[7]
I2CDIS
Bit 7
UI[7]
ID[7]
LDX
--
--
--
--
--
XOUT[6]
YOUT[6]
ZOUT[6]
XOUT[6]
YOUT[6]
ZOUT[6]
TMP[6]
DAD[6]
Bit 6
UI[6]
ID[6]
LDY
--
--
--
--
--
4. PCB layout of power and ground should not couple
5. Accelerometer and microcontroller should not be a
6. Any external power supply switching frequency
XOUT[5]
YOUT[5]
ZOUT[5]
XOUT[5]
YOUT[5]
ZOUT[5]
TMP[5]
DAD[5]
power supply noise.
high current path.
should be selected such that they do not interfere
with the internal accelerometer sampling frequency
(sampling frequency). This will prevent aliasing
errors.
Bit 5
UI[5]
ID[5]
LDZ
--
--
--
--
--
XOUT[4]
YOUT[4]
ZOUT[4]
XOUT[4]
YOUT[4]
ZOUT[4]
TMP[4]
DAD[4]
Bit 4
UI[4]
ID[4]
PDX
--
--
--
--
--
XOUT[3]
YOUT[3]
ZOUT[3]
XOUT[3]
YOUT[3]
ZOUT[3]
TMP[3]
DAD[3]
Bit 3
PDY
UI[3]
ID[3]
--
--
--
--
--
XOUT[2]
YOUT[2]
ZOUT[2]
XOUT[2]
YOUT[2]
ZOUT[2]
TMP[2]
DAD[2]
PERR
Freescale Semiconductor
Bit 2
UI[2]
ID[2]
PDZ
--
--
--
--
XOUT[1]
XOUT[9]
YOUT[1]
YOUT[9]
XOUT[1]
YOUT[1]
ZOUT[1]
ZOUT[9]
ZOUT[1]
TMP[1]
DAD[1]
DOVR
Bit 1
INT1
UI[1]
ID[1]
--
XOUT[0]
XOUT[8]
YOUT[0]
YOUT[8]
ZOUT[0]
ZOUT[8]
XOUT[0]
YOUT[0]
ZOUT[0]
Sensors
TMP[0]
DAD[0]
DRDY
Bit 0
INT2
UI[0]
ID[0]
--