14W HI-FI AUDIO AMPLIFIER

TDA2003(C)

 

第 7 页  共 11 页 

BUILT-IN PROTECTION SYSTEMS (Cont.)

THERMAL SHUT-DOWN

The presence of a thermal limiting circuit offers the following advantages:

An overload on the output (even if it is permanent),or an excessive ambient temperature can be easily

withstood.

The heat-sink can have a smaller factor compared with that of a conventional circuit. There is no device

damage in case of excessive junction temperature: all that happens is that Po ( and therefore PD) and Id are

reduced

COMPONENTS USAGE SUGGESTION

The recommended values of the components are those shown on typical application circuit Different values

can be used. The following table can help the designer.

COMPONEN

T

RECOMMEND

ED VALUE

PURPOSE

LARGE THAN

RECOMMENDED

VALUE

SMALLER THAN

RECOMMENDED

VALUE

R1

(Gv-1)*R2

Gain setting.

increase of drain

current

R2

2.2Ω

gain and SVR setting

Decrease of SVR

R3

1Ω

Frequency stability

Danger of oscillation at

high frequencies with

inductive loads.

Rx

≈20R2

Upper frequency cutoff

Poor high frequencies

attenuation

Danger of oscillation

C1

2.2μF

Input DC decoupling

Noise at switch-on

switch-of

C2

470μF

Ripple rejection

Decrease of SVR

C3

0.1μF

Supply voltage bypass

Danger of oscillation

C4

1000μF

Supply voltage bypass

Higher low frequency

cutoff

C5

0.1μF

Frequency stability

Danger of oscillation at

high frequencies with

inductive loads.

Cx

≈1/(2π*B*R1)

Upper frequency cut of

Lower bandwidth

Larger bandwidth