TDA1908
8W AUDIO AMPLIFIER
DESCRIPTION
The TDA1908 is a monolithic integrated circuit in
12 lead quad in-line plastic package intended for
low frequency power applications. The mounting is
compatible with the old types TBA800, TBA810S,
TCA830S and TCA940N. Its main features are:
flexibility in use with a max output curent of 3A
and an operating supply voltage range of 4V to
30V;
protection against chip overtemperature;
soft limiting in saturation conditions;
low "switch-on" noise;
low number of external components;
high supply voltage rejection;
very low noise.
March 1993
Symbol
Parameter
Value
Unit
V
s
Supply voltage
30
V
I
o
Output peak current (non repetitive)
3.5
A
I
o
Output peak current (repetitive)
3
A
P
tot
Power dissipation: at T
amb
= 80
C
1
W
at T
amb
= 90
C
5
W
T
stg
, T
j
Storage and junction temperature
-40 to 150
C
ABSOLUTE MAXIMUM RATINGS
APPLICATION CIRCUIT
Findip
ORDERING NUMBER : TDA1908
1/12
2/12
PIN CONNECTION (top view)
SCHEMATIC DIAGRAM
TDA1908
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
= 18V
V
s
= 30V
1.6
8.2
14.4
2.1
9.2
15.5
2.5
10.2
16.8
V
I
d
Quiescent drain current
V
s
= 4V
V
s
= 18V
V
s
= 30V
15
17.5
21
35
mA
V
CEsat
Output stage saturation voltage
(each output transistor)
I
C
= 1A
I
C
= 2.5A
0.5
1.3
V
P
o
Output power
d = 10%
f = 1KHz
V
s
= 9V
R
L
= 4
V
s
= 14V
R
L
= 4
V
s
= 18V
R
L
= 4
V
s
= 22V
R
L
= 8
V
s
= 24V
R
L
= 16
7
6.5
4.5
2.5
5.5
9
8
5.3
W
ELECTRICAL CHARACTERISTICS (Refer to the test circuit, T
amb
= 25
C, R
th
(heatsink)= 8
C/W, unless
otherwise specified)
(
) Obtained with tabs soltered to printed circuit board with min copper area.
Symbol
Parameter
Value
Unit
R
th j-tab
Thermal resistance junction-tab
max
12
C/W
R
th j-amb
Thermal resistance junction-ambient
max
(
) 70
C/W
THERMAL DATA
TEST CIRCUIT
* See fig. 12
3/12
TDA1908
4/12
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
d
Harmonic distorsion
f = 1KHz
V
s
= 9V
R
L
= 4
P
o
= 50 mW to 1.5 W
V
s
= 18V
R
L
= 4
P
o
= 50 mW to 4W
V
s
= 24V
R
L
= 16
P
o
= 50 mW to 3W
0.1
0.1
0.1
%
V
i
Input sensivity
V
s
= 9V
V
s
= 14V
V
s
= 18V
V
s
= 22V
V
s
= 24V
R
L
= 4
R
L
= 4
R
L
= 4
R
L
= 8
R
L
= 16
P
o
= 2.5W
P
o
= 5.5W
P
o
= 9W
P
o
= 8W
P
o
= 5.3W
37
52
64
90
110
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 resistence (pin 8)
f = 1 KHz
60
100
K
I
s
Drain current
f = 1 KHz
V
s
= 14V
V
s
= 18V
V
s
= 22V
V
s
= 24V
R
L
= 4
R
L
= 4
R
L
= 8
R
L
= 16
P
o
= 5.5W
P
o
= 9W
P
o
= 8W
P
o
= 5.3W
570
730
500
310
mA
Efficiency
V
s
= 18V
f = 1 KHz
R
L
= 4
P
o
= 9W
72
%
BW
Small signal bandwitdth (-3 dB)
V
s
= 18V
R
L
= 4
P
o
= 1W
40 to 40 000
Hz
G
v
Voltage gain (open loop)
f = 1 KHz
75
dB
G
v
Voltage gain (closed loop)
V
s
= 18V
f = 1 KHz
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
= 18V
P
o
= 9W
R
L
= 4
R
g
= 10K
R
g
= 0
(
)
92
94
dB
R
g
= 10K
R
g
= 0
(
)
88
90
dB
SVR
Supply voltage rejection
V
s
= 18V
R
L
= 4
f
ripple
= 100 Hz
R
g
= 10K
40
50
dB
T
sd
Termal shut-down junction
temperature
(*)
145
C
ELECTRICAL CHARACTERISTICS (continued)
Note :
(
)
Weighting filter = curve A.
(
) Filter with noise bandwidth: 22 Hz to 22 KHz.
TDA1908
Figure 1. Quiescent output
voltage vs. supply voltage
Figure 2. Quiescent drain
current vs. supply voltage
Figure 3. Output power vs.
supply voltage
Fi gur e 4 . Di stor tion v s.
output power (R
L
= 16
)
Fi gur e 5 . D isto rtion vs .
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
)
Fi gur e 8 . D isto rtion vs .
frequency (R
L
= 8
)
Fi gur e 9 . D isto rtion vs .
frequency (R
L
= 4
)
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TDA1908
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