Thomson TDA2040 User Manual

20W Hi-Fi AUDIOPOWER AMPLIFIER

DESCRIPTION

The TDA2040 is a monolithicintegrated circuit in
Pentawatt package,intendedforuse asan audio
class ABamplifier.Typicallyit provides22W output
power (d = 0.5%) at V
provides high output current and has very low
harmonic and cross-over distortion. Further the
deviceincorporatesapatentedshortcircuitprotec­tion system comprising an arrangement for auto­maticallylimitingthedissipatedpowersoastokeep
the working point of the output transistors within
their safe operating area. A thermal shut-down
system is also included.

TEST CIRCUIT

= 32V/4Ω . The TDA2040

s

TDA2040

PENTAWATT

ORDERING NUMBER : TDA2040V

December 1995

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TDA2040

SCHEMATICDIAGRAM

PIN CONNECTION

THERMALDATA

Symbol Parameter Value Unit

R

th j-case

Thermal Resistance Junction-case Max. 3 °C/W

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TDA2040

ABSOLUTEMAXIMUM RATINGS

Symbol Parameter Value Unit

V

s

V
V

I

o

P

tot

T

stg,Tj

ELECTRICALCHARACTERISTICS
(refer to the testcircuit, V

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

s

I

d

I

b

V

os

I

os

P

o

BW Power Bandwidth P

G

v

G

v

d Total Harmonic Distortion P

e

N

i

N

R

i

SVR Supply Voltage Rejection R

η Efficiency f = 1kHz

T

j

Supply Voltage ± 20 V
Input Voltage V

i

DifferentialInput Voltage ± 15 V

i

s

Output Peak Current (internally limited) 4 A
Power Dissipation at T

=75°C25W

case

Storage and Junction Temperature – 40 to + 150 °C

= ± 16V, T

S

=25oC unlessotherwise specified)

amb

Supply Voltage ± 2.5 ± 20 V
Quiescent Drain Current Vs= ± 4.5V

= ± 20V 4530100mAmA

V

s

Input Bias Current Vs= ± 20V 0.3 1 µA
Input Offset Voltage Vs= ± 20V ± 2 ± 20 mV
Input Offset Current ± 200 nA
Output Power d = 0.5%, T

f = 1kHz R
f = 15kHz R

= 1W, RL=4Ω 100 kHz

o

case

=60°C

=4Ω

L

=8Ω

R

L

=4Ω

L

201522

12
18

Open Loop Voltage Gain f = 1kHz 80 dB
Closed Loop Voltage Gain f = 1kHz 29.5 30 30.5 dB

= 0.1to 10W, RL=4Ω

o

f = 40 to 15000Hz
f = 1kHz

Input Noise Voltage B = Curve A

B = 22Hz to 22kHz

Input Noise Current B = Curve A

B = 22Hz to 22kHz

0.08

0.03
2

310

50
80 200

Input Resistance (pin 1) 0.5 5 MΩ

=4Ω,Rg= 22kΩ,Gv= 30dB

L

f = 100Hz, V

P

= 12W RL=8Ω

o

= 22W RL=4Ω

P

o

ripple

= 0.5V

RMS

40 50 dB

66
63

Thermal Shut-down JunctionTemperature 145 °C

W

%

µV
µV

pA

%

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TDA2040

Figure1 : OutputPower versus Supply Voltage Figure 2 : OutputPower versus Supply Voltage

Figure3 : OutputPower versus Supply Voltage Figure 4 : Distortion versus Frequency

Figure5 : Supply Voltage Rejectionversus

Frequency

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Figure6 : SupplyVoltage Rejectionversus

VoltageGain

TDA2040

Figure7 : QuiescentDrain Current versus

Supply Voltage

Figure9 : PowerDissipation versusOutput

Power

Figure8 : OpenLoop Gain versus Frequency

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TDA2040

Figure10 : Amplifier with Split Power Supply

Figure11: P.C.Boardand Components Layoutfor the Circuit of Figure 10 (1:1 scale)

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Figure12 : Amplifier with Split Power Supply (see Note)

Note : In this case of highly inductive loadsprotection diodes may be necessary.

Figure13 : P.C.Board and Components Layout for the Circuit of Figure 12 (1:1 scale)

TDA2040

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TDA2040

Figure14 : 30W Bridge Amplifierwith Split Power Supply

Figure15 : P.C.Board and Components Layout for the Circuit of Figure 14 (1:1 scale)

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Figure16 : TwoWayHi-Fi System with Active Crossover

TDA2040

Figure 17 : P.C. Boardand ComponentsLayout for the Circuit of Figure 16 (1:1 scale)

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TDA2040

Figure18 : FrequencyResponse Figure19 : PowerDistribution versus Frequency

MULTIWAY SPEAKERSYSTEMS AND ACTIVE
BOXES

Multiway loudspeaker systems provide the best
possible acoustic performance since each loud­speaker is specially designed and optimized to
handle a limited range of frequencies.Commonly,
these loudspeakersystems dividetheaudio spec­truminto two, three or four bands.

TomaintainaflatfrequencyresponseovertheHi-Fi
audio range the bands covered by each loud­speakermust overlap slightly. Imbalancebetween
the loudspeakers produces unacceptable results
therefore it is important to ensure that each unit
generates the correct amount of acoustic energy
for its segment of the audio spectrum. In this re­spect it is also important to know the energy distri­bution of the music spectrum determine the cutoff
frequenciesofthecrossoverfilters (seeFigure19).
As an example, a 100W three-way system with
crossover frequencies of 400Hz and 3kHz would
require50W for the woofer, 35Wfor the midrange
unitand 15W for the tweeter.

Both active and passive filters can be used for
crossoversbut today activefilters costsignificantly
less than a good passivefilter using air-cored in­ductorsandnon-electrolyticcapacitors.Inaddition,
active filters do not suffer from the typicaldefects
of passive filters :

- powerloss

- increased impedance seen by the loudspeaker
(lowerdamping)

- difficulty of precise design due to variable loud­speakerimpedance

Obviously,active crossovers can only be used if a

poweramplifierisprovidedfor eachdriveunit.This
makes it particularly interesting and economically
soundto use monolithic power amplifiers. In some
applications, complex filters are not really neces­sary and simple RC low-pass and high-pass net­works(6dB/octave) can be recommended.

The results obtained are excellent because this is
the best type of audio filter and the only one free
from phase and transientdistortion.

The rather poor out of band attenuation of single
RC filters means that the loudspeakermust oper­ate linearlywell beyondthe crossoverfrequencyto
avoid distortion.

A more effective solution, named ”Active Power
Filter” by SGS is shownin Figure20.

Figure20 : Active PowerFilter

The proposed circuit can realize combined power
amplifiers and 12dB/octave or 18dB/octave high­pass or low-pass filters.

In practice, at the input pins of the amplifier two
equal and in-phase voltages are available, as re­quiredfor the activefilter operation.

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TDA2040

Theimpedanceat thepin (-)isoftheorderof 100Ω,

PRATICALCONSIDERATION

while that of the pin (+) is very high, which is also
what was wanted.

C1 = C2 = C3 R1 R2 R3

22 nF 8.2 kΩ 5.6 kΩ 33 kΩ

The component values calculated for fc= 900Hz
using a Bessel 3rd order Sallenand Key structure

PrintedCircuit Board

The layout shown in Figure11 should be adopted
by the designers. If different layouts are used, the
groundpoints of input 1 and input 2 must be well
decoupledfrom the gorund return of the outputin

whicha high current flows.
are :
In theblock diagram ofFigure21isrepresentedan

activeloudspeakersystemcompletely realizedus­ing power integrated circuit, rather than the tradi­tional discrete transistors on hybrids, very high

AssemblySuggestion

No electrical isolationis neededbetweenthe pack-

age and the heatsink with single supply voltage

configuration.
quality is obtained by driving the audio spectrum
into three bands using active crossovers
(TDA2320A) and a separate amplifier and loud­speakersfor each band.

A modern subwoofer/midrange/tweetersolution is
used.

ApplicationSuggestions

The recommended values of the components are

those shown on application circuit of Fig. 10. Dif-

ferentvaluescan be used. The followingtable can

help the designer.

Figure21 : High Power Active LoudspeakerSystem usingTDA2030Aand TDA2040

Comp.

C3, C4 0.1µF Supply voltage bypass Danger of oscillation
C5, C6 220µF Supply voltage bypass Danger of oscillation

(*) The value of closed loop gain must be higher than 24dB

Recom.

Value

R1 22kΩ Non inverting input biasing Increase of input impedance Decrease of input impedance
R2 680Ω Closed loop gain setting Decrease of gain (*) Increase of gain
R3 22kΩ Closedloop gain setting Increase of gain Decrease of gain (*)
R4 4.7Ω Frequency stability Danger of oscillation at high

C1 1µF InputDC decoupling Increase of low frequencies cut-off
C2 22µF Inverting DC decoupling Increase of low frequencies cut-off

C7 0.1µF Frequency stability Danger of oscillation

Purpose

frequencies with inductive loads

Larger than

Recommended Value

Smaller than

Recommended Value

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TDA2040

PENTAWATT PACKAGE MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

mm inch

A 4.8 0.189
C 1.37 0.054
D 2.4 2.8 0.094 0.110

D1 1.2 1.35 0.047 0.053

E 0.35 0.55 0.014 0.022
F 0.8 1.05 0.031 0.041

F1 1 1.4 0.039 0.055

G 3.4 0.126 0.134 0.142
G1 6.8 0.260 0.268 0.276
H2 10.4 0.409
H3 10.05 10.4 0.396 0.409

L 17.85 0.703
L1 15.75 0.620
L2 21.4 0.843
L3 22.5 0.886
L5 2.6 3 0.102 0.118
L6 15.1 15.8 0.594 0.622
L7 6 6.6 0.236 0.260

M 4.5 0.177

M1 4 0.157

Dia 3.65 3.85 0.144 0.152

A

H3

L

L1

C

D1

L5

Dia.

L7

L6

L2
L3

D

F1

H2

E

MM1

G1

G

F

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TDA2040

Information furnished is believedto be accurate andreliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringementof patents or other rights of third parties which may result from its use. No
licenseis granted by implication or otherwiseunder any patent or patent rights of SGS-THOMSONMicroelectronics. Specifications men­tioned in this publication are subject to change without notice.This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without ex­press written approval of SGS-THOMSON Microelectronics.

 1996 SGS-THOMSONMicroelectronics All Rights Reserved

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