TDA8190 ST Microelectronics, TDA8190 Datasheet - Page 7

• Manufacturer Part Number: TDA8190
• Description: TV SOUND CHANNEL WITH DC CONTROLS
• Manufacturer: ST Microelectronics

Figure 13 : Power Dissipation versus Supply
Figure 15 : Quiescent Drain and Quiescent Out-
APPLICATION INFORMATION
(refer to the block diagram)
IF Amplifier-limiter
It is made by six differential stages of 15dB gain
each so that an open loop gain of 90dB is obtained.
While a unity DC gain is provided, the AC closed
loop gain is internally fixed at 70dB that allows a
typical input sensitivity of 50 V.
The differential output signal is single ended by a
20dB gain amplifier that through a buffer stage,
feeds the detector system.
Internal diodes protect the inputs against over-
loads.
- Pin 2 is the IF non-inverting input
- Pin 3 is decoupled by a capacitor to open the AC
- Pin 4 grounded by a capacitor, allows a typical
4
3
2
1
0
20
15
10
loop
5
0
8
P
8
d = 10%
tot
V o
V = 0
P2 = 12k
10 12 14 16 18 20 22 24 26 28
R = 8
i
(W)
L
12
Voltage (sine wave operation)
put Voltage versus Supply Voltage
16
20
I S
R = 16
L
24
I
S
V (V)
V o
s
(mA)
V (V)
s
28
33
32
31
30
29
Low-pass Filter, Fm Detector And Amplifier
The IF signal is detected by converting the fre-
quency modulation into amplitude modulation and
then detecting it.
Since the available modulated signal is a square
wave, a 40 dB/decade low-pass filter cuts its har-
monics so that a sine wave can feed the two-reso-
nances external network L1, C8 and C9.
This network defines the working frequency value,
the amplitude of the recovered audio signal and its
distortion at the highest frequency deviations.
The two resonances f1 (series resonance) and f2
(parallel resonance) can be computed respectively
by :
Figure 14 : Power Dissipation and Efficiency
3
2.5
2
1.5
1
0
sensitivity of 50 V. (see VCR facility too).
P
R = 16
tot
L
X
(W)
C9
1
versus Output Power
X
X
L1
L1
2
X
X
C8
C8
and X
3
P tot
L1
= X
4
P (W)
o
TDA8190
C8
(%)
5
100
7/11
80
60
40
20
0