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6 supply ripple rejection – Texas Instruments APA100 User Manual

Page 41

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Supply Ripple Rejection

5-7

Measured Results

5.6

Supply Ripple Rejection

The APA100 uses a closed loop which keeps the gain from changing with
supply voltage and improves the supply ripple rejection ratio (k

SRR

) over an

open−loop class-D amplifier. The supply ripple rejection ratio versus
frequency curve is shown in Figure 5−9.

Figure 5−9. APA100 Supply Ripple Rejection Ratio vs Frequency With 8-

W

Load

0

−10

−20

−30

−40

−50

−60

−70

−80

20

100

200

1 k

2 k

10 k 20 k

k

SR

− Supply V

oltage Rejection Ratio − V

f − Frequency − Hz