R3

IN (L)

C1

R2

C3

MUTE/

ST-BY

GND

IN (R)

C2

R7

R10

C8

C9

OUT (L)

OUT (R)

C6

C4

3

5

7

9

6

11

2

4

+

+

-

-

D94AU087

RL (L)

RL (R)

R9

R5

IN- (L)

8

10

IN- (R)

1

SW1

R1

DZ

R4

SW2

C7

R8

R6

C5

Figure 4: Test and Application Circuit (Stereo Configuration).

APPLICATIONS SUGGESTION

(Demo Board Schematic)

The recommended values of the external compo-

nents are those shown are the demo board sche-

matic different values can be used: the following

table can help the designer.

COMPONENTS

RECOMMENDED

VALUE

PURPOSE

LARGER THAN

RECOMMENDED VALUE

SMALLER THAN

RECOMMENDED VALUE

R1

10K

Ω

Mute Circuit

Increase of Dz

Biasing Current

R2

15K

Ω

Mute Circuit

R3

18K

Ω

Mute Circuit

R4

15K

Ω

Mute Circuit

R5, R8

18K

Ω

Closed Loop Gain

Setting (*)

Increase of Gain

R6, R9

560

Ω

Decrease of Gain

R7, R10

4.7

Ω

Frequency Stability

Danger of Oscillations

Danger of Oscillations

C1, C2

1

µF

Input DC

Decoupling

Higher Low Frequency

Cutoff

C3

1

µF

St-By/Mute Time

Constant

Larger On/Off Time

Smaller On/Off Time

C4, C6

1000

µF

Supply Voltage

Bypass

Danger of Oscillations

C5, C7

0.1

µF

Supply Voltage

Bypass

Danger of Oscillations

C8, C9

0.1

µF

Frequency Stability

Dz

5.1V

Mute Circuit

(*) Closed loop gain has to be => 25dB

TDA7499

5/7