TDA1905
5W AUDIO AMPLIFIER WITH MUTING
DESCRIPTION
The TDA1905 is a monolithic integrated circuit in
POWERDIP package, intended for use as low
frequency power amplifier in a wide range of appli-
cations in radio and TV sets:
muting facility
protection against chip over temperature
very low noise
high supply voltage rejection
low "switch-on" noise
voltage range 4V to 30V
The TDA 1905 is assembled in a new plastic pack-
age, the POWERDIP, that offers the same assembly
ease, space and cost saving of a normal dual in-line
package but with a power dissipation of up to 6W and
a thermal resistance of 15
C/W (junction to pins).
March 1993
Symbol
Parameter
Value
Unit
V
s
Supply voltage
30
V
I
o
Output peak current (non repetitive)
3
A
I
o
Output peak current (repetitive)
2.5
A
V
i
Input voltage
0 to + V
s
V
V
i
Differential input voltage
7
V
V
11
Muting thresold voltage
V
s
V
P
tot
Power dissipation at T
amb
= 80
C
1
W
T
case
= 60
C
6
W
T
stg
, T
j
Storage and junction temperature
-40 to 150
C
ABSOLUTE MAXIMUM RATINGS
APPLICATION CIRCUIT
Powerdip
(8 + 8)
ORDERING NUMBER : TDA 1905
1/14
Symbol
Parameter
Value
Unit
R
th-j-case
Thermal resistance junction-pins
max
15
C/W
R
th-j-amb
Thermal resistance junction-ambient
max
70
C/W
THERMAL DATA
2/14
PIN CONNECTION (top view)
SCHEMATIC DIAGRAM
TDA1905
TEST CIRCUITS:
WITHOUT MUTING
WITH MUTING FUNCTION
3/14
TDA1905
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
V
s
Supply voltage
4
30
V
V
o
Quiescent output voltage
V
s
= 4V
V
s
= 14V
V
s
= 30V
1.6
6.7
14.4
2.1
7.2
15.5
2.5
7.8
16.8
V
I
d
Quiescent drain current
V
s
= 4V
V
s
= 14V
V
s
= 30V
15
17
21
35
mA
V
CE sat
Output stage saturation
voltage
I
C
= 1A
I
C
= 2A
0.5
1
V
P
o
Output power
d = 10%
V
s
= 9V
V
s
= 14V
V
s
= 18V
V
s
= 24V
f = 1KHz
R
L
= 4
(*)
R
L
= 4
R
L
= 8
R
L
= 16
2.2
5
5
4.5
2.5
5.5
5.5
5.3
W
d
Harmonic distortion
f = 1KHz
V
s
= 9V
R
L
= 4
P
o
= 50 mW to 1.5W
V
s
= 14V
R
L
= 4
P
o
= 50 mW to 3W
V
s
= 18V
R
L
= 8
P
o
= 50 mW to 3W
V
s
= 24V
R
L
= 16
P
o
= 50 mW to 3W
0.1
0.1
0.1
0.1
%
V
i
Input sensitivity
f = 1KHz
V
s
= 9V
V
s
= 14V
V
s
= 18V
V
s
= 24V
R
L
= 4
R
L
= 4
R
L
= 8
R
L
= 16
P
o
= 2.5W
P
o
= 5.5W
P
o
= 5.5W
P
o
= 5.3W
37
49
73
100
mV
V
i
Input saturation
voltage (rms)
V
s
= 9V
V
s
= 14V
V
s
= 18V
V
s
= 24V
0.8
1.3
1.8
2.4
V
R
i
Input resistance (pin 8)
f = 1KHz
60
100
K
I
d
Drain current
f = 1KHz
V
s
= 9V
V
s
= 14V
V
s
= 18V
V
s
= 24V
R
L
= 4
R
L
= 4
R
L
= 8
R
L
= 16
P
o
= 2.5W
P
o
= 5.5W
P
o
= 5.5W
P
o
= 5.3W
380
550
410
295
mA
Efficiency
f = 1KHz
V
s
= 9V
V
s
= 14V
V
s
= 18V
V
s
= 24V
R
L
= 4
R
L
= 4
R
L
= 8
R
L
= 16
P
o
= 2.5W
P
o
= 5.5W
P
o
= 5.5W
P
o
= 5.3W
73
71
74
75
%
ELECTRICAL CHARACTERISTICS (Refer to the test circuit, T
amb
= 25
C, R
th
(heatsink) = 20
C/W,
unless otherwisw specified)
(*) With an external resistor of 100
between pin 3 and +V
s
.
4/14
TDA1905
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
BW
Small signal
bandwidth (-3dB)
V
s
= 14V
R
L
= 4
P
o
= 1W
40 to 40,000
Hz
G
v
Voltage gain (open loop)
V
s
= 14V
f = 1KHz
75
dB
G
v
Voltage gain (closed loop)
V
s
= 14V
f = 1KHz
R
L
= 4
P
o
= 1W
39.5
40
40.5
dB
e
N
Total input noise
R
g
= 50
R
g
= 1K
R
g
= 10K
(
)
1.2
1.3
1.5
4.0
V
R
g
= 50
R
g
= 1K
R
g
= 10K
(
)
2.0
2.0
2.2
6.0
V
S/N
Signal to noise ratio
V
s
= 14V
P
o
= 5.5W
R
L
= 4
R
g
= 10K
R
g
= 0
(
)
90
92
dB
R
g
= 10K
R
g
= 0
(
)
87
87
dB
SVR
Supply voltage rejection
V
s
= 18V
R
L
= 8
f
ripple
= 100 Hz
Rg = 10K
V
ripple
= 0.5V
rms
40
50
dB
T
sd
Thermal shut-down
case temperatura
(*)
P
tot
= 2.5W
115
C
MUTING FUNCTION
VT
OFF
Muting-off threshold
voltage (pin 4)
1.9
4.7
V
VT
ON
Muting-on threshold
voltage (pin 4)
0
1.3
V
6.2
V
s
R
5
Input-resistance (pin 5)
Muting off
80
200
K
Muting on
10
30
R
4
Input resistance (pin 4)
150
K
A
T
Muting attenuation
R
g
+ R
1
= 10K
50
60
dB
ELECTRICAL CHARACTERISTICS (continued)
Note:
(
)
Weighting filter = curve A.
(
) Filter with noise bandwidth: 22 Hz to 22 KHz.
(*)
See fig. 30 and fig. 31
5/14
TDA1905
Figure 1. Quiescent output
voltage vs. supply voltage
Figure 2. Quiescent drain
current vs. supply voltage
Figure 3. Output power vs.
supply voltage
Fi g ure 4. Dist ort ion v s.
output power (R
L
= 16
)
Fig ur e 5 . Di stor tion v s.
output power (R
L
= 8
)
Fi gur e 6 . D isto rtion vs .
output power (R
L
= 4
)
Fi g ure 7. Dist ort ion v s.
frequency (R
L
= 16
)
Fig ur e 8 . Di stor tion v s.
frequency (R
L
= 8
)
Fi gur e 9 . D isto rtion vs .
frequency (R
L
= 4
)
6/14
TDA1905
Figure 10. Open loop fre-
quency response
Figure 11. Output power vs.
input voltage
Figure 12. Value of capaci-
tor Cx vs. bandwidth (BW)
and gain (Gv)
Figure 13. Supply voltage re-
jection vs. voltage gain (ref.
to the Muting circuit)
Figure 14. Supply voltage re-
ection vs. source resistance
Figure 15. Max power dissi-
pation vs. supply voltage
(sine wave operation)
Figure 16. Power dissipa-
tion and efficiency vs. output
power
Figure 17. Power dissipa-
tion and efficiency vs. output
power
Figure 18. Power dissipa-
tion and efficiency vs. output
power
7/14
TDA1905
8/14
APPLICATION INFORMATION
Figure 19. Application circuit without muting
Figure 20. PC board and components lay-out
of the circuit of fig. 19 (1 : 1 scale)
Figure 21. Application circuit with muting
Figure 22. Delayed muting circuit
TDA1905
APPLICATION INFORMATION (continued)
Figure 23. Low-cost application circuit without bootstrap.
Figure 25. Two position DC tone control using change of
pin 5 resistance (muting function)
Figure 27. Bass Bomb tone control using change of pin 5
resistance (muting function)
Figure 24. Output power
vs. supply voltage (circuit
of fig. 23)
Figure 26. Frequency re-
sponseof the circuit of fig. 25
Figure 28. Frequency re-
sponseof thecircuit of fig. 27
9/14
TDA1905
10/14
MUTING FUNCTION
The output signal can be inhibited applying a DC voltage V
T
to pin 4, as shown in fig. 29
Figure 29
The input resistance at pin 5 depends on the threshold voltage V
T
at pin 4 and is typically :
R
5
= 200 K
@
1.9V
V
T
4.7V
muting-off
R5 =
10
@
0V
VT
1.3V
muting-on
6V
VT
V
s
Referring to the following input stage, the possible attenuationof the input signal and therefore of the output
signal can be found using the following expression:
Considering R
g
= 10 K
the attenuation in the
muting-on condition is typically A
T
= 60 dB. In the
muting-off condition, the attenuation is very low,
typically 1.2 dB.
A very low current is necessary to drive the thresh-
old voltage V
T
because the input resistance at pin
4 is greater than 150 K
. The muting function can
be usedin many cases, when a temporaryinhibition
of the output signal is requested, for example:
in switch-on condition, to avoid preamplifier
power-on transients (see fig. 22)
A
T
=
V
i
V
8
=
R
g
+ (
R
8
R
5
R
8
+
5
)
(
R
8
R
5
R
8
+
R
5
)
where R8
100 K
during switching at the input stages.
during the receiver tuning.
The variable impedance capability at pin 5 can be
useful in many applications and two examples are
shown in fig. 25 and 27, where it has been used to
change the feedback network, obtaining 2 different
frequency responses.
TDA1905
APPLICATION SUGGESTION
The recommended values of the external components are those shown on the application circuit of fig. 21.
When the supply voltage V
s
is less than 10V, a 100
resistor must be connected between pin 2 and pin 3
in order to obtain the maximum output power.
Different values can be used. The following table can help the designer.
Component
Raccom.
value
Purpose
Larger than
recommended value
Smaller than
recommended value
Allowed range
Min.
Max.
R
g
+ R
1
10K
Input signal imped.
for muting operation
Increase of the
attenuation in muting-on
condition. Decrease of
the input sensitivity.
Decrease of the attenu-
ation in muting on
condition.
R
2
10K
Feedback resistors
Increase of gain.
Decrease of gain.
Increase quiescent
current.
9 R
3
R
3
100
Decrease of gain.
Increase of gain.
1K
R
4
1K
Frequency stability
Danger of oscillation at
high frequencies with
inductive loads.
R
5
100
Increase of the output
swing with low supply
voltage.
47
330
P
1
20K
Volume potentiometer
Increase of the
switch-on noise.
Decrease of the input
impedance and of the
input level.
10K
100K
C
1
C
2
C
3
0.22
F
Input DC
decoupling.
Higher cost
lower noise.
Higher low
frequency cutoff.
Higher noise.
C
4
2.2
F
Inverting input DC
decoupling.
Increase of the switch-
on noise.
Higher low frequency
cutoff.
0.1
F
C
5
0.1
F
Supply voltage
bypass.
Danger of
oscillations.
C
6
10
F
Ripple rejection
Increase of SVR
increase of the
switch-on time
Degradation of SVR
2.2
F
100
F
C
7
47
F
Bootstrap.
Increase of the
distortion at low
frequency.
10
F
100
F
C
8
0.22
F
Frequency stability.
Danger of oscillation.
C
9
1000
F
Output DC decoupling.
Higher low frequency
cutoff.
11/14
TDA1905
12/14
THERMAL SHUT-DOWN
The presence of a thermal limiting circuit offers the following advantages:
1) An overload on the output (even if it is permanent), or an above limit ambient temperature can be easily
tolerated since the Tj cannot be higher than 150
C.
2) The heatsink can have a smaller factor of safety compared with that of a conventional circuit. There is
no possibility of device damage due to high junction temperature.
If for any reason, the junction temperatureincreases up to 150
C, the thermal shut-down simply reduces
the power dissipation and the current consumption.
The maximum allowable power dissipation depends upon the size of the external heatsink (i.e. its thermal
resistance); fig. 32 shows this dissipable power as a function of ambient temperature for different thermal
resistance.
Figure 30. Output power
and drain current vs. case
temperature
Figure 31. Output power
and drain current vs. case
temperature
Figure 32. Maximum allo-
wable power dissipation
vs. ambient temperature
MOUNTING INSTRUCTION : See TDA1904
TDA1905
DIM.
mm
inch
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
a1
0.51
0.020
B
0.85
1.40
0.033
0.055
b
0.50
0.020
b1
0.38
0.50
0.015
0.020
D
20.0
0.787
E
8.80
0.346
e
2.54
0.100
e3
17.78
0.700
F
7.10
0.280
I
5.10
0.201
L
3.30
0.130
Z
1.27
0.050
POWERDIP PACKAGE MECHANICAL DATA
13/14
TDA1905
14/14
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences 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 SGS-THOMSON Microelectronics. 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.
1994 SGS-THOMSON Microelectronics - All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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TDA1905
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