BUILT-IN PROTECTION SYSTEMS

THERMAL SHUT-DOWN

The presence of a thermal limiting circuit offers

the following advantages:

1-an overload on the output (even if it is perma-

nent), or an excessive ambient temperature

can be easily withstood.

2-the heatsink can have a smaller factor of

safety compared with that of a conventional

circuit. There is no device damage in the case

of excessive junction temperature; all that

are reduced.

SHORT CIRCUIT (AC CONDITIONS)

The TDA7263M can withstand accidental short

circuits across the speaker made by a wrong con-

nection during normal play operation.

APPLICATION SUGGESTION

The recommended values of the components are those shown on application circuit of figure 1. Different

values can be used; the following table can help the designer.

Component

Recomm.

Value

Purpose

Larger Than

Smaller Than

R1 and R3

1.5K

Ω

Close loop gain setting (*)

Increase of gain

Decrease of gain

R2 and R4

47

Ω

Close loop gain setting (*)

Decrease of gain

Increase of gain

R5 and R6

4.7

Ω

Frequency stability

Danger of oscillations

C1 and C2

100nF

Input DC decoupling

Higher SVR

Higher low frequency cutoff

C3

47

µF

- Ripple Rejection

- Mute time constant

Increase of the Switch-on

time

- Degradation of SVR

- Worse turn-off pop by muting

C4

100nF

Supply Voltage Bypass

Danger of oscillations

C5

1000

µF

Supply Voltage Bypass

C6 and C7

47

µF

Feedback input DC

decoupling

Increase of the Switch-on

time

Decrease of the Switch-on

time

C8 and C9

0.1

µF

Frequency stability

Danger of oscillations

C10 and C11

1000

µF

Output DC decoupling

Higher low-frequency cut-off

(*) Closed loop gain must be higher than 26dB

Figure 8: P. C. Board and Component Layout of the Application Circuit (1:1 scale).

TDA7263M

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