8/14

BD5632NUX, BD5634NUX, BD5638NUX

www.rohm.com

2010.06 - Rev.A

© 2010 ROHM Co., Ltd. All rights reserved.

Technical Note

●

The way of evaluating Audio characteristic

Evaluation Circuit Diagram

When measuring Audio characteristics, insert LC filter during the output terminal of IC and the speaker load and measure it.

Arrange LC filter as close as possible to the output terminal of IC.

In case of L=22µH, C=1µF, the cut-off frequency becomes the following.

Use a big current type - Inductor L.

(Reference)

TDK : SLF12575T-220M4R0

STBY

IN+

IN-

OUT-

OUT+

Bias

OSC

PWM

H-

Bridge

0.47μ

0.47μ

Differential

Input

H：Active

L：Shutdown

Audio

Input+

Audio

Input-

GND

VDD

10μ

1

3

4

8

5

0.1μ

VDD

VDD

C2

C1

C3

7

C4

6

300k

Ri=100k

Ri=100k

22μH

22μH

1μF

1μF

Audio

Precision

etc

RL=Speaker Load

Measument Instrumen

+

-

kHz

34

μF

1

μH

22

2

1

LC

2

1

fc









π

π