MMA955xL

Sensors

Freescale Semiconductor, Inc.

13

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Minimize PCB trace lengths for high-frequency signals. This is especially critical in systems with higher capacitive loads that

•

•

and digital power and ground planes as close as possible to power supply outputs. If both analog circuit and digital circuits

•

Physically separate the analog components from noisy digital components by ground planes. Do not place an analog trace

in parallel with digital traces. It is also desirable to place an analog ground trace around an analog signal trace to isolate it

from digital traces.

•

Provide an interface to the BKGD/MS pin if in-circuit debug capability is desired.

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configuration, the value of 4.7 k

Ω would be appropriate.

3.4.3

MMA955xL Platform as an Intelligent Slave

The basic configurations are shown in the following two figures. In addition, the RGPIO pins can be programmed to generate

interrupts to a host platform in response to the occurrence of real-time application events. In this case, the pins should be routed

to the external interrupt pins of the CPU.

Quiet VDDA for

best performance

1.8V

1.8V

1.8V

1.8V

1.8V

C4

1μF

C3

0.1μF

U1

MMA955X

1

3

4

5

2

9

10

11

12

13

VDD

RESETB

SCL0/IO0/SCLK

VSS

BKGD/MS/IO9

IO4/INT

VSS

IO5/PDB_A/INT_O

IO6/AN0

IO7/AN1

R2

4.7KΩ

R3

4.7KΩ

L1

10μFBEAD

1

2

C1

1μF

C2

0.1μF

R1

4.7KΩ

R4

4.7KΩ

INT_OUT

I2C_CLK

I2C_DATA