TELEFUNKEN Semiconductors
TDA4445A/TDA4445B
Rev. A1: 14.09.1995
1 (8)
Quasi Parallel Sound Processing with Quadrature
Intercarrier Demodulator
Technology:
Bipolar
Features
D Very high input sensitivity
D Excellent signal to noise ratio
D Fast averaged AGC
D IF amplifier can be switched off for VTR mode
D Output signal stabilized against V
S
variations
D Very few external components
TDA4445B additional
D Targeting bistandard applications (B/G and L)
D Alignment free AM demodulator
D Low AM distortion
Case:
DIP16
Figure 1. Block diagram TDA4445A
Figure 2. Block diagram TDA4445B
TELEFUNKEN Semiconductors
TDA4445A/TDA4445B
Rev. A1: 14.09.1995
2 (8)
Pin Description
Pin
Symbol
Function
116
IF input
3
If AGC time constant
89
Tuned circuit
11
Supply voltage
12
Sound-IF-output
13
Ground
2, 4,
7, 10,
14, 15
not connected
TDA4445B additional
Pin
Symbol
Function
5
Average capacitor
6
AF output
Circuit Description
This circuit includes the following functions
D Three symmetrical and gain controlled wide band
amplifier stages, which are extremely stable by quasi
DC coupling without feedback
D Averaged AGC with discharge control circuit
D AGC voltage generator
Quasi parallel sound operation
D High phase accuracy of the carrier signal processing,
independent from AM
D Linear quadrature demodulator
D SoundIFamplifier stage with impedance converter
AMDemodulation (TDA4445B only)
D Carrier controlled demodulator
D Audio frequency stage with impedance converter
D Averaged low pass AGC
Absolute Maximum Ratings
Reference point pin 3, unless otherwise specified
Parameters
Symbol
Value
Unit
Supply voltage range
Pin 11
V
S
10 ... 15
V
Supply current
Pin 11
I
S
70
mA
External voltages
TDA4445A, B
Pin 3
Pin 12
TDA4445B only
Pin 5, 6
V
ext
12
8
8
V
Power dissipation in soldered position
P
tot
1
W
Junction temperature
T
j
125
C
Ambient temperature range
T
amb
25 to +70
C
Storage temperature range
T
stg
25 to +125
C
Thermal Resistance
Parameters
Symbol
Value
Unit
Junction ambient
R
thJA
60
K/W
TELEFUNKEN Semiconductors
TDA4445A/TDA4445B
Rev. A1: 14.09.1995
3 (8)
Electrical Characteristics
V
S
= 12 V,
T
amb
= + 25
C, reference point pin 13, unless otherwise specified
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Supply current
V
116
= 10 mV
or V
3
= 3.5 V
Pin 11
I
S
60
mA
DC output voltage
V
116
= 10 mV,
unmodulated
Pin 12
V
O
5.0
V
DC output current
V
11
= 7.5 V,
V
3
= 3.5 V
Pin 12
I
max
1.8
V
Input impedance
Pin 116
Pin 116
R
C
1.6
2.0
k
W
PF
Switch off control voltage
VTR mode
Pin 3
V
8
10
V
Switch off control current
VTR mode
Pin 3
I
50
150
mA
Quasi Parallel Sound Operation
f
PC
= 38.9 MHz, f
SC1
= 33.4 MHz, f
SC2
= 33.16 MHz, PC/SC = 13 dB, PC/SC2 = 20 dB,
PC unmodulated (equivalent to sync. peak current)
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Minimum input voltage
5.5 MHz output signal
3dB
Pin 116
v
i
50
mV
Maximum input voltage
5.5 MHz output signal
+1 dB
Pin 116
v
i
80
mV
IF AGC range
G
IF
64
dB
AGC capacitor
control time constant, Pin 3
C
3
0.33
10
mF
Sound-IF-output voltage V
116
= 10 mV, SC unmodulated
5.5 MHz output voltage
Pin 12
v
i
250
mV
5.74 MHz output voltage
i
110
Signal to noise ratio: measured according to CCIR 4682
reference signal: v
116
= 10 mV, FM-frequency deviation = +30 kHz
f
mod
= 1 kHz, measured at audio-output sound IF demodulator U2829B
1. Channel/ 2. Channel
Standard B/G modulated IF signal
(residual carrier 10%)
Black screen
Pin 12
Grid pattern
S+N
N
62/58
52/49
dB
Bistandard Operation
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
IF AGC range
G
IF
64
dB
AGC capacitor
(control time constant)
Pin 3
Pin 5
C
3
C
5
10
4.7
mF
TELEFUNKEN Semiconductors
TDA4445A/TDA4445B
Rev. A1: 14.09.1995
4 (8)
Quasi Parallel Sound Operation
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
f
PC
= 38.9 MHZ, f
SCI
= 33.4 MHZ, f
SC2
= 33.16 MHz,
PC/SC= 13 dB, PC/SC2= 20 dB, PC unmodulated (equivalent to sync. peak current)
Minimum input voltage
Maximum input voltage
5.5 MHz output signal
3dB
Pin 116
+1dB
Pin 116
v
i
v
i
50
80
mV
mV
Sound-IF-output voltage
v
116
= 10 mV,
Pin 12
SC unmodulated,
5.5 MHz signal
5.74 MHz signal
v
250
110
mV
AM-Demodulation
f
SC
= 39.2 MHz, m
=
80 %, f
mod
= 1 kHz
Parameters
Test Conditions / Pin
Symbol
Min.
Typ.
Max.
Unit
Minimum input voltage
Audio output signal 3dB
Pin 116
v
50
mV
DC output voltage
v
116
= 10 mV,
unmodulated
Pin 6
V
4.1
V
DC output current
V
6
= 7.5 V, V
3
= 3.5 V
Pin 6
I
max
0.65
mA
Distortion
v
116
= 10 mV, m =80 %,
f
mod
= 1 kHz
Pin 6
d
1.5
3.0
%
AF output voltage
v
116
= 10 mV, m = 80 %,
f
mod
= 1 kHz
Pin 6
v
850
mV
TELEFUNKEN Semiconductors
TDA4445A/TDA4445B
Rev. A1: 14.09.1995
5 (8)
Figure 3. Quasi parallel sound operation
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