TDA7240A
December 1998
20W BRIDGE AMPLIFIER FOR CAR RADIO
.
COMPACT HEPTAWATT PACKAGE
.
FEW EXTERNAL COMPONENTS
.
OUTPUT PROTECTED AGAINST SHORT
CIRCUITS TO GROUND AND ACROSS LOAD
.
DUMP TRANSIENT
.
THERMAL SHUTDOWN
.
LOUDSPEAKER PROTECTION
.
HIGH CURRENT CAPABILITY
.
LOW DISTORTION/LOW NOISE
DESCRIPTION
Heptawatt H
Heptawatt V
ORDERING NUMBERS:
TDA7240AH
TDA7240AV
The TDA7240A is a 20W bridge audio amplifier IC
designed specially for car radio applications.
Thanks to the low external part count and compact
Heptawatt 7-pin power package the TDA7240A
occupies little space on the printed circuit board.
Reliable operation is guaranteed by a comprehen-
sive array of on-chip protection features. These in-
clude protection against AC and DC output short
circuits (to ground and across the load), load dump
transients, and junction overtemperature. Additio-
nally, theTDA7240Aprotectstheloudspeakerwhen
one output is short-circuited to ground.
Figure 1: Test and Application Circuit
1/8
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
s
Operating Supply Voltage
18
V
V
s
DC Supply Voltage
28
V
V
s
Peak Supply Voltage (for 50ms)
40
V
I
o
(*)
Peak Output Current (non repetitive t = 0.1ms)
4.5
A
I
o
(*)
Peak Output Current (repetitive f
10Hz)
3.5
A
P
tot
Power Dissipation at Tcase = 85
C
16
W
T
stg
, T
j
Storage and Junction Temperature
40 to 150
C
(*) Internally limited
PIN CONNECTION (Top view)
THERMAL DATA
Symbol
Parameter
Value
Unit
R
th j-case
Thermal Resistance Junction-case
Max.
4
V
TDA7240A
2/8
ELECTRICAL CHARACTERISTICS (refer to the circuit of fig. 1, T
amb
= 25
C, R
th
(heatsink) = 4
C/W,
V
s
= 14.4V)
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
s
Supply Voltage
18
V
V
os
Output Offset Voltage
150
mV
I
d
Total Quiescent Current
R
L
= 4
65
120
mA
P
o
Output Power
f = 1kHz; d = 10%
R
L
= 4
R
L
= 8
18
10
20
12
W
W
d
Distortion
R
L
= 4
f = 1kHz
P
o
= 50mW to 12W
0.1
0.5
%
R
L
= 8
f = 1kHz
P
o
= 50mW to 12W
0.05
0.5
%
GV
Voltage Gain
f = 1KHz
39.5
40
40.5
dB
SVR
Supply Voltage Rejection
f = 100Hz
R
g
= 10K
35
40
dB
E
N
Total Input Noise
R
g
= 10K
(*)
(**)
2
3
10
V
V
Efficiency
R
L
= 4
f = 1KHz
65
%
I
sb
Stand-by Current
200
A
R
i
Input Resistance
f = 1kHz
70
k
V
i
Input Sensitivity
f = 1kHz; P
o
= 2W; R
L
= 4
28
mV
f
L
Low Frequency Roll Off
(3dB)
Po = 15W;
R
L
= 4
30
Hz
f
H
High Frequency Roll Off
(3dB)
Po = 15W;
RL = 4
25
kHz
A
s
Stand-by Attenuation
V
o
= 2Vrms
70
90
dB
V
TH (pin2)
Stand-by Threshold
1
V
(*) B= Curve A
(**) B = 22Hz to 22 KHz
Figure 2 : P.C. Board and Components layout of the Circuit of Fig. 1.(1:1scale)
TDA7240A
3/8
APPLICATION SUGGESTION
The recommendedvalues of the componentsare thoseshown on application circuit of Fig. 1. Different values
can be used, the following table can help the designer.
Component
Recommended
Value
Purpose
Larger Than
Smaller Than
R1, R2
2.2
Frequency Stability
Danger of High
Frequency Oscillation
C1
1
F
Input DC Decoupling
Higher Turn On and
Stand-by Delay
Higher Turn On Pop.
Higher Low
Frequency Cutoff
C2
22
F
Ripple Rejection
Increase of SVR
Increase of the Turn
On Delay
Degradation of SVR
C3
22
F
Feedback low
Frequency Cutoff
Higher Low Frequency
Cutoff
C6, C7
0.22
F
Frequency Stability
Danger of Oscillation
C4
220
F
Supply Filter
Danger of Oscillation
C5
0.1
F
Supply Bypass
Danger of Oscillation
Figure 4 : Distortion vs. Output Power.
Figure 3 : Output Power vs. Supply Voltage.
Figure 6 : Distortion vs. Output Power.
Figure 5 : Output Power vs. Supply voltage.
TDA7240A
4/8
Figure 8 : Supply Voltage Rejection
vs. Frequency.
Figure 7 : Distortion vs. Frequency.
Figure 10 : Power Dissipation and Efficiency vs.
Output Power.
Figure 9 : Power Dissipation and Efficiency vs.
Output Power.
TDA7240A
5/8
Heptawatt V
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
E1
0.7
0.97
0.028
0.038
F
0.6
0.8
0.024
0.031
F1
0.9
0.035
G
2.34
2.54
2.74
0.095
0.100
0.105
G1
4.88
5.08
5.28
0.193
0.200
0.205
G2
7.42
7.62
7.82
0.295
0.300
0.307
H2
10.4
0.409
H3
10.05
10.4
0.396
0.409
L
16.7
16.9
17.1
0.657
0.668
0.673
L1
14.92
0.587
L2
21.24
21.54
21.84
0.386
0.848
0.860
L3
22.27
22.52
22.77
0.877
0.891
0.896
L4
1.29
0.051
L5
2.6
2.8
3
0.102
0.110
0.118
L6
15.1
15.5
15.8
0.594
0.610
0.622
L7
6
6.35
6.6
0.236
0.250
0.260
L9
0.2
0.008
M
2.55
2.8
3.05
0.100
0.110
0.120
M1
4.83
5.08
5.33
0.190
0.200
0.210
V4
40
(typ.)
Dia
3.65
3.85
0.144
0.152
A
L
L1
C
D1
L5
L2
L3
D
E
M1
M
H3
Dia.
L7
L6
F1
H2
F
G
G1
G2
E1
F
E
L9
V4
L4
H2
V
V
HEPTAMEC
H1
OUTLINE AND
MECHANICAL DATA
TDA7240A
6/8
Heptawatt H
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
0.6
0.8
0.024
0.031
F1
0.9
0.035
G
2.41
2.54
2.67
0.095
0.100
0.105
G1
4.91
5.08
5.21
0.193
0.200
0.205
G2
7.49
7.62
7.8
0.295
0.300
0.307
H2
10.4
0.409
H3
10.05
10.4
0.396
0.409
L
14.2
0.559
L1
4.4
0.173
L2
15.8
0.622
L3
5.1
0.201
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
L9
4.44
0.175
Dia
3.65
3.85
0.144
0.152
OUTLINE AND
MECHANICAL DATA
TDA7240A
7/8
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the conse-
quences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this
publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMi-
croelectronics products are not authorized for use as critical components in life support devices or systems without express written
approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
HEPTAWATT
TM
is a Trademark of SGS-THOMSON Microelectronics
1998 STMicroelectronics Printed in Italy All Rights Reserved
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TDA7240A
8/8
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