TDA4445A
TDA4445B
SOUND IF AMPLIFIER
December 1992
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
IF INPUT
NOT TO BE CONNECTED
IF AGC TIME CONSTANT
NOT TO BE CONNECTED
REFERENCE L.C. NETWORK
REFERENCE L.C. NETWORK
NOT TO BE CONNECTED
SUPPLY VOLTAGE
FM MODULATED SOUND OUTPUT
GROUND
IF INPUT
NOT TO BE CONNECTED
NOT TO BE CONNECTED
NOT TO BE CONNECTED
NOT TO BE CONNE CTED FOR TDA4445A
AVE RAGING CAP ACITOR FOR TDA4445B
NOT TO BE CONNE CTED FOR TDA4445A
A.F. SOUND OUTPU T FOR TDA4445B
4445-01.EPS
PIN CONNECTIONS
DIP16
(Plastic Package)
ORDER CODE : TDA4445A - TDA4445B
.
QUADRATURE INTERCARRIER DEMODU-
LATOR
.
VERY HIGH INPUT SENSITIVITY
.
GOOD SIGNAL TO NOISE RATIO
.
FAST AVERAGING AGC
.
IF AMPLIFIER CAN BE SWITCHED OFF FOR
VTR MODE
.
GOOD AM SUPPRESSION
.
OUTPUT
SIGNAL
STABILIZED
AGAINST
SUPPLY VOLTAGE VARIATIONS
.
VERY FEW EXTERNAL COMPONENTS
DESCRIPTION
TDA4445A :
Sound IF amplifier, with FM processing for quasi
parallel sound system.
TDA4445B :
Sound IF amplifier, with FM processing and AM
demodulator, for multi-standard sound TV appli-
ances.
TDA4445B additionnal :
Bistandard applications (B/G and L)
No adjustment of the AM demodulator
Low AM distortion
1/6
4445-02.EPS
/
4445-03.EPS
BLOCK DIAGRAMS
GENERAL DESCRIPTION
This circuit includes the following functions :
.
Three symmetrical and gain controlled wide
band amplifier stages, which are extremely sta-
ble by quasi DC coupling without feedback.
.
Averaging AGC with discharge control circuit
.
AGC voltage generator
Quasi parallel sound operation :
.
High phase accuracy of the carrier signal proc-
essing, independent from AM
.
Linear quadrature demodulator
.
Sound-IF-amplifier stage with impedance con-
verter
AM-Demodulation (only TDA4445B) :
.
Carrier controlled demodulator
.
Audio frequency stage with impedance con-
verter
.
Averaging low pass AGC
TDA4445A
TDA4445B
TDA4445A - TDA4445B
2/6
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage Range
Pin 11
15
V
I
CC
Supply Current
Pin 11
70
mA
V
ext
External Voltages
Pin 3
Pin 12
12
8
V
V
V
ext
External Voltages
TDA4445A - TDA4445B
TDA4445B
Pin 5
Pin 6
8
8
V
V
P
to t
Power Dissipation
1
W
T
j
Junction Temperature
125
C
T
amb
Ambient Temperature Range
0, + 70
C
T
stg
Storage Temperature Range
25, + 125
C
4445-01.TBL
THERMAL DATA
Symbol
Parameter
Value
Unit
R
th(j-a)
Junction-ambient Thermal Resistance
70
C/W
4445-02.TBL
ELECTRICAL OPERATING CHARACTERISTICS
T
amb
= + 25
C, V
CC
= 12V (unless otherwise specified)
Symbol
Parameter
Min.
Typ.
Max.
Unit
DC CHARACTERISTICS
V
CC
Supply Voltage
Pin 13
10
12
15
V
I
CC
Supply Current (V
3
= 3.5V)
Pin 11
45
60
mA
V
O
DC Output Voltage (V
3
= 3.5V)
Pin 12
4.25
5
5.75
V
I
Output DC Current (V
3
= 3.5VV
11
= 12V)
Pin 12
1
2
mA
R
Input Impedance
Pins 1-16
2
k
C
Input Impedance
Pins 1-16
2
pF
V
Switch off Control Voltage for VTR Mode
Pin 3
9
10
V
I
Switch off Control Current for VTR Mode
Pin 3
150
A
AGC CHARACTERISTICS
GIF
IF AGC Range
62
dB
QUASI PARALLEL SOUND OPERATION
(f
PC
= 38.9MHz, f
SC1
= 33.4MHz, f
SC2
= 33.16MHz, PC/SC
1
= 13dB, PC/SC2 = 20dB, PC unmodulated)
V
I
Min. Input Voltage (5.5MHz - Output Signal - 3dB)
Pins 1-16
70
V
eff
V
I
Max. Input Voltage (5.5MHz - Output Signal + 1dB)
Pins 1-16
90
mV
eff
V
O
Sound-IF-output Voltage (V
1-16
= 20mV
eff
SC unmodulated)
5.5MHz Output Voltage
5.74MHz Output Voltage
Pin 12
200
100
400
300
mV
eff
mV
eff
S
+
N
N
Signal to noise ratio measured according to CCIR 468-2
Picture Modulation Ratio 90%, Reference signal (V
1-16
= 10mV),
FM-frequency deviation30kHz
Out 1 350mV
RMS
f
mod
= 1kHz, measured at audio-output
Out 2 350mV
RMS
Black Screen (1. Channel/2. Channel)
Grid Screen (1. Channel/2. Channel)
Pin 12
55/50
45/40
dB
dB
AM DEMODULATI0N (TDA4445B only) (f
SC
= 39.2MHz, m = 80%, f
mod
= 1kHz)
V
I
Min. Input Voltage (Audio Output Signal - 3dB)
Pins 1-16
70
V
eff
V
O
Output DC Voltage (V
1-16
= 10mV
eff
unmodulated)
Pin 6
3.3
4.5
V
I
Output DC Current (V
6
= 7.5V, V
3
= 3.5V)
Pin 6
0.3
1.2
mA
d
Distortion (V
1-16
= 10mV, f
mod
= 1kHz , m = 80%)
Pin 6
2.5
4
%
V
O
AF Output Voltage (V
1-16
= 100mV
eff
, m = 50% , f
mod
= 10kHz)
Pin 6
500
700
900
mV
eff
4445-03.TBL
TDA4445A - TDA4445B
3/6
4445-04.TIF
TYPICAL APPLICATION
Figure 1 : Quasi Parallel Sound Operation
TDA4445A - TDA4445B
4/6
4445-05.TIF
TYPICAL APPLICATION
Figure 2 : Bistandard Operation (FM stereo sound + AM sound)
TDA4445A - TDA4445B
5/6
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