APPLICATION NOTE: (ref. fig. 7)

Modular Application (more Devices in Parallel)

The use of the modular application lets very high

power be delivered to very low impedance loads.

The modular application implies one device to act

as a master and the others as slaves.

The slave power stages are driven by the master

device and work in parallel all together, while the

input and the gain stages of the slave device are

disabled, the figure below shows the connections

required to configure two devices to work to-

gether.

The master chip connections are the same as

the normal single ones.

The outputs can be connected together with-

out the need of any ballast resistance.

The slave SGND pin must be tied to the nega-

tive supply.

The slave ST-BY pin must be connected to

ST-BY pin.

The bootstrap lines must be connected to-

gether and the bootstrap capacitor must be in-

creased: for N devices the boostrap capacitor

must be 22

µF times N.

The slave Mute and IN-pins must be grounded.

THE BOOTSTRAP CAPACITOR

For compatibility purpose with the previous de-

vices of the family, the boostrap capacitor can be

connected both between the bootstrap pin (6) and

the output pin (14) or between the boostrap pin

(6) and the bootstrap loader pin (12).

IN-

2

R2

680

Ω

C2

22

µF

C1 470nF

IN+

R1 22K

3

R3 22K

-

+

MUTE

STBY

4

10

9

SGND

MUTE

STBY

R4 22K

THERMAL

SHUTDOWN

S/C

PROTECTION

R5 10K

C3 10

µF

C4 10

µF

1

STBY-GND

C5

47

µF

713

14

6

15

8

-Vs

-PWVs

BOOTSTRAP

OUT

+PWVs

+Vs

C9 100nF

C8 1000

µF

-Vs

D97AU808C

+Vs

C7 100nF

C6 1000

µF

BUFFER

DRIVER

11

BOOT

LOADER

12

IN-

2

IN+

3

-

+

MUTE

STBY

4

10

9

SGND

MUTE

THERMAL

SHUTDOWN

S/C

PROTECTION

1

STBY-GND

713

14

6

15

8

-Vs

-PWVs

BOOTSTRAP

OUT

+PWVs

+Vs

C9 100nF

C8 1000

µF

-Vs

+Vs

C7 100nF

C6 1000

µF

BUFFER

DRIVER

11

BOOT

LOADER

12

5

CLIP DET

5

MASTER

SLAVE

C10

100nF

R7

2

Ω

VMUTE

VSTBY

STBY

Figure 6: Modular Application Circuit

TDA7296S

8/11