TDA7245A
6W AUDIO AMPLIFIER WITH STAND-BY
STAND-BY FUNCTION
SUPPLY VOLTAGE RANGE UP TO 30V
MUSIC POWER = 16W (R
L
= 4
, d = 10%)
THERMAL PROTECTION
DESCRIPTION
The TDA7245A is a monolithic integrated circuit
in 9+9 POWERDIP package, intended for use as
low frequency power amplifier in a wide range of
applications in radio and TV sets.
May 1997
Figure 1: Test and Application Circuit
Powerdip 9+9
ORDERING NUMBER: TDA7245A
1/6
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
S
Supply Voltage
30
V
I
O
Output Peak Current (non repetitive t = 100
s)
3
A
I
O
Output Peak Current (repetitive, f > 20Hz)
2.5
A
P
tot
Power Dissipation at T
amb
= 80
C
at T
case
= 70
C
1
6
W
W
T
stg
, T
j
Storage and junction Temperature
-40 to 150
C
PIN CONNECTION (Top view)
THERMAL DATA
Symbol
Description
Value
Unit
R
th j-case
Rth j-amb
Thermal Resistance junction-case
Thermal Resistance junction-ambient
Max
Max
15
70
C/W
C/W
Figure 2: Schematic Diagram
TDA7245A
2/6
ELECTRICAL CHARACTERISTICS (Refer to the test circuit, T
amb
= 25
C, V
S
= 16.5V, R
L
= 4
, f =
1kHz; unless otherwise specified).
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
S
Supply Voltage
12
30
V
V
O
Quiescent Output Voltage
V
S
= 24V
11.6
V
I
d
Quiescent Drain Current
V
S
= 28V
24
35
mA
P
O
Output Power
d = 1%
V
S
= 16.5V, R
L
= 4
V
S
= 20V, R
L
= 8
d = 10%
V
S
= 16.5V, R
L
= 4
V
S
= 20V, R
L
= 8
Music Power (*)
V
S
= 24V, d = 10%, R
L
= 4
6.5
6
5
7.5
6.5
16
W
W
W
W
W
d
Harmonic Distortion
P
O
= 50mW to 4W
f = 1KHz
f = 10KHz
V
S
= 20V, R
L
= 8
,
P
O
= 50mW to 3.5W
f = 1KHz
f = 10KHz
0.15
0.8
0.12
0.5
0.5
%
%
%
%
R
I
Input Impedance
f = 1kHz
30
K
BW
Small signal bandwidth (-3dB)
P
O
= 1W
20 to 40,000
Hz
G
V
Voltage Gain (open loop)
f = 1KHz
75
dB
G
V
Voltage Gain (closed loop)
f = 1KHz
39
40
41
dB
e
N
Total Input Noise
B = 22 - 22,000Hz
R
s
= 50
R
s
= 1k
R
s
= 10k
1.7
2
3
6
mV
V
V
S/N
Signal to Noise Ratio
P
O
= 5W; R
S
= 10K
86
dB
SVR
Supply Voltage Rejection
V
S
= 16.5V; R
L
= 8
; f = 100Hz
R
s
= 10k
;
V
r
= 0.5Vrms
38
45
dB
T
sd
Thermal shut-down Junction
Temperature
150
C
STAND-BY FUNCTION
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
st-by
Pin 5 DC Voltage
SW1 Open (play)
6.4
V
I
st- by
Pin 5 Current
SW1 Closed (st-by)
160
280
A
ATT
st-by
Stand-by Attenuation
f = 1kHz
70
90
dB
V
t
Stand-by Threshold (pin 5)
3.8
V
I
d st-by
Quiescent Current @ Stand-by
2
4
mA
Note (*):
MUSIC POWER CONCEPT
MUSIC POWER is ( according to the IEC clauses n.268-3 of Jan 83) the maximal power which the amplifier is capable of producing across the
rated load resistance (regardless of non linearity) 1 sec after the application of a sinusoidal input signal of frequency 1KHz.
According to this definition our method of measurement comprises the following steps:
1) Set the voltage supply at the maximum operating value -20%
2) Apply a input signal in the form of a 1KHz tone burst of 1 sec duration; the repetition period of the signal pulses is > 60 sec
3) The output voltage is measured 1 sec from the start of the pulse
4) Increase the input voltage until the output signal show a THD = 10%
5) The music power is then V
2
out
/R1
,
where V
out
is the output voltage measured in the condition of point 4) and R1 is the rated load impedance
The target of this method is to avoid excessive dissipation in the amplifier.
TDA7245A
3/6
PDF 
ZIP
