Sensors

Freescale Semiconductor

21

MMA7455L

SENSING DIRECTION AND OUTPUT RESPONSE

The following figure shows sensing direction and the

output response for 2g mode.

Figure 18. Sensing Direction and Output Response at 2g Mode

Table 7. Acceleration vs. Output

FS Mode

Acceleration

Output

2g Mode

-2g

$80

-1g

$C1

0g

$00

+1g

$3F

+2g

$7F

4g Mode

-4g

$80

-1g

$E1

0g

$00

+1g

$1F

+4g

$7F

8g Mode

-8g

$80

-1g

$F1

0g

$00

+1g

$0F

+8g

$7F

Side View

X

OUT

@0g=$00

Y

OUT

@ +1g = $3F

Z

OUT

@0g=$00

X

OUT

@ +1g = $3F

Y

OUT

@0g=$00

Z

OUT

@0g=$00

X

OUT

@ -1g = $C1

Y

OUT

@0g=$00

Z

OUT

@ 0g = $00

1

6

5432

13

12

11

10

9

8

14

7

X

OUT

@0g=$00

Y

OUT

@ -1g = $C1

Z

OUT

@0g=$00

Direction of Earth's gravity field.*

Top View

X

OUT

@0g=$00

Y

OUT

@0g=$00

Z

OUT

@ -1g = $C1

X

OUT

@0g=$00

Y

OUT

@0g=$00

Z

OUT

@ +1g = $3F

16

5

4

3

2

13 12 11 10

9

8

14

7

Top

Top

Bottom

Bottom

* When positioned as shown, the Earth’s gravity will result in a positive 1g output.