THOMSON TDA2040 User manual

TDA2040
20W Hi-Fi AUDIO POWER AMPLIFIER
December 1995
PENTAWATT
ORDERING NUMBER : TDA2040V
DESCRIPTION
The TDA2040 is a monolithic integrated circuit in
Pentawattpackage,intendedforuseasanaudio
class ABamplifier.Typically it provides22Woutput
power (d = 0.5%) at Vs= 32V/4Ω. The TDA2040
provides high output current and has very low
harmonic and cross-over distortion. Further the
deviceincorporatesapatentedshort circuitprotec-
tion system comprising an arrangementfor auto-
maticallylimitingthe dissipatedpowersoas tokeep
the working point of the output transistors within
their safe operating area. A thermal shut-down
system is also included.
TEST CIRCUIT
1/13

SCHEMATIC DIAGRAM
PIN CONNECTION
THERMAL DATA
Symbol Parameter Value Unit
Rth j-case Thermal Resistance Junction-case Max. 3 °C/W
TDA2040
2/13

ELECTRICAL CHARACTERISTICS
(refer to the testcircuit, VS=±16V, Tamb =25o
C unlessotherwise specified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VsSupply Voltage ±2.5 ±20 V
IdQuiescent Drain Current Vs=±4.5V
Vs=±20V 45 30
100 mA mA
IbInput Bias Current Vs=±20V 0.3 1 µA
Vos Input Offset Voltage Vs=±20V ±2±20 mV
Ios Input Offset Current ±200 nA
PoOutput Power d = 0.5%, Tcase =60°C
f = 1kHz RL=4Ω
R
L=8Ω
f = 15kHz RL=4Ω
20
15
22
12
18
W
BW Power Bandwidth Po= 1W, RL=4Ω100 kHz
GvOpen Loop Voltage Gain f = 1kHz 80 dB
GvClosed Loop Voltage Gain f = 1kHz 29.5 30 30.5 dB
d Total Harmonic Distortion Po= 0.1 to 10W, RL=4Ω
f = 40 to 15000Hz
f = 1kHz 0.08 0.03
%
eNInput Noise Voltage B = Curve A
B = 22Hz to 22kHz 2 310
µV
µV
i
NInput Noise Current B = Curve A
B = 22Hz to 22kHz 50 80 200 pA
RiInput Resistance (pin 1) 0.5 5 MΩ
SVR Supply Voltage Rejection RL=4Ω,R
g= 22kΩ,G v= 30dB
f = 100Hz, Vripple = 0.5VRMS 40 50 dB
ηEfficiency f = 1kHz
Po= 12W RL=8Ω
P
o= 22W RL=4Ω66
63
%
TjThermal Shut-down Junction Temperature 145 °C
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
VsSupply Voltage ±20 V
ViInput Voltage Vs
ViDifferentialInput Voltage ±15 V
IoOutput Peak Current (internally limited) 4 A
Ptot Power Dissipation at Tcase =75°C25W
T
stg,T jStorage and Junction Temperature – 40 to + 150 °C
TDA2040
3/13

Figure1 : Output Power versus SupplyVoltage Figure 2 : Output Powerversus Supply Voltage
Figure3 : Output Power versus SupplyVoltage Figure 4 : Distortion versus Frequency
Figure5 : Supply Voltage Rejection versus
Frequency Figure 6 : SupplyVoltage Rejection versus VoltageGain
TDA2040
4/13

Figure7 : QuiescentDrain Current versus
Supply Voltage Figure 8 : OpenLoop Gain versus Frequency
Figure9 : Power Dissipation versus Output
Power
TDA2040
5/13

Figure10 : Amplifier with Split Power Supply
Figure11 : P.C. Board and Components Layoutfor the Circuit of Figure 10 (1:1 scale)
TDA2040
6/13

Note : In this case of highly inductive loadsprotection diodes may be necessary.
Figure12 : Amplifier with Split Power Supply (see Note)
Figure13 : P.C.Board and Components Layoutfor the Circuit of Figure 12 (1:1 scale)
TDA2040
7/13

Figure14 : 30W Bridge Amplifierwith Split Power Supply
Figure15 : P.C.Board and Components Layoutfor the Circuit of Figure 14 (1:1 scale)
TDA2040
8/13

Figure16 : Two Way Hi-Fi System with Active Crossover
Figure 17 : P.C. Boardand ComponentsLayout for the Circuit of Figure 16 (1:1 scale)
TDA2040
9/13

Figure18 : Frequency Response Figure 19 : Power Distribution versus Frequency
MULTIWAY SPEAKER SYSTEMS AND ACTIVE
BOXES
Multiway loudspeaker systems provide the best
possible acoustic performance since each loud-
speaker is specially designed and optimized to
handle a limited range of frequencies.Commonly,
these loudspeakersystems divide the audio spec-
truminto two, three or four bands.
To maintainaflatfrequencyresponseovertheHi-Fi
audio range the bands covered by each loud-
speakermust overlapslightly. 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 re-
spect it is also important to know the energy distri-
bution of the music spectrum determine the cutoff
frequenciesof thecrossoverfilters (see Figure 19).
As an example, a 100W three-way system with
crossover frequencies of 400Hz and 3kHz would
require 50W for the woofer, 35W for the midrange
unit and 15W for the tweeter.
Both active and passive filters can be used for
crossovers but today active filters cost significantly
less than a good passive filter using air-cored in-
ductorsandnon-electrolyticcapacitors.Inaddition,
active filters do not suffer from the typical defects
of passive filters :
- powerloss
- increased impedance seen by the loudspeaker
(lowerdamping)
- difficulty of precise design due to variable loud-
speakerimpedance
Obviously, active crossovers can only be used if a
poweramplifieris providedforeachdriveunit.This
makes it particularly interesting and economically
soundto use monolithicpoweramplifiers. In some
applications, complex filters are not really neces-
sary and simple RC low-pass and high-pass net-
works (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 phaseand transientdistortion.
The rather poor out of band attenuation of single
RC filters means that the loudspeakermust oper-
ate linearly well beyondthe crossoverfrequencyto
avoid distortion.
A more effective solution, named ”Active Power
Filter” bySGS is shownin Figure 20.
Figure 20 : Active Power Filter
The proposed circuit can realize combined power
amplifiers and 12dB/octave or 18dB/octave high-
pass or low-pass filters.
In practice, at the input pins of the amplifier two
equal and in-phase voltages are available, as re-
quiredfor the activefilter operation.
TDA2040
10/13

Theimpedanceat thepin(-)isoftheorderof100Ω,
while that of the pin (+) is very high, which is also
what was wanted.
C1 = C2 = C3 R1 R2 R3
22 nF 8.2 kΩ5.6 kΩ33 kΩ
The component values calculated for fc= 900Hz
using a Bessel 3rd order Sallenand Key structure
are :
In theblock diagramof Figure 21is representedan
active loudspeakersystem completely realized us-
ing power integrated circuit, rather than the tradi-
tional discrete transistors on hybrids, very high
quality is obtained by driving the audio spectrum
into three bands using active crossovers
(TDA2320A) and a separate amplifier and loud-
speakersfor eachband.
A modern subwoofer/midrange/tweetersolution is
used.
PRATICALCONSIDERATION
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
which a high current flows.
Assembly Suggestion
No electrical isolation isneededbetween thepack-
age and the heatsink with single supply voltage
configuration.
Application Suggestions
The recommended values of the components are
those shown on applicationcircuit of Fig. 10. Dif-
ferentvaluescan be used. The following table can
help the designer.
Figure21 : High PowerActive LoudspeakerSystem usingTDA2030Aand TDA2040
Comp. Recom.
Value Purpose Larger than
Recommended Value Smaller than Recommended Value
R1 22kΩNon inverting input biasing Increase of input impedance Decrease of input impedance
R2 680ΩClosedloop gain setting Decrease of gain (*) Increase of gain
R3 22kΩClosed loop gain setting Increase of gain Decrease of gain (*)
R4 4.7ΩFrequency stability Danger of oscillation at high
frequencies with inductive loads
C1 1µF InputDC decoupling Increase of low frequencies cut-off
C2 22µF Inverting DC decoupling Increase of low frequencies cut-off
C3, C4 0.1µF Supply voltage bypass Danger of oscillation
C5, C6 220µF Supplyvoltage bypass Danger of oscillation
C7 0.1µF Frequency stability Danger of oscillation
(*) The value of closed loop gain must be higher than 24dB
TDA2040
11/13

L2
L3
L5
L7
L6
Dia.
A
C
D
E
D1
H3
H2
F
G
G1
L1
L
MM1
F1
PENTAWATT PACKAGE MECHANICAL DATA
DIM. mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
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
TDA2040
12/13

Information furnished is believedto be accurate andreliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences ofuse of suchinformation nor for any infringementof patents or other rights of third parties which may result fromits use. No
license is granted by implication or otherwiseunder any patent or patentrights of SGS-THOMSON Microelectronics. Specifications men-
tioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are notauthorized for use as critical components in life support devices or systems withoutex-
press written approval of SGS-THOMSON Microelectronics.
1996 SGS-THOMSON Microelectronics All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
Australia - Brazil - Canada -France - Germany - HongKong - Italy - Japan - Korea - Malaysia- Malta - Morocco - The Netherlands -
Singapore - Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A.
TDA2040
13/13