SGS Thomson Microelectronics TDA4445A, TDA4445B Datasheet
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QUADRATURE INTERCARRIER DEMODULATOR
.
VERYHIGHINPUTSENSITIVITY
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GOODSIGNALTO NOISE RATIO
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FASTAVERAGINGAGC
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IF AMPLIFIERCAN BE SWITCHED OFF FOR
VTRMODE
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GOODAM SUPPRESSION
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OUTPUT SIGNAL STABILIZED AGAINST
SUPPLY VOLTAGEVARIATIONS
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VERYFEW EXTERNALCOMPONENTS
DESCRIPTION
TDA4445A:
Sound IF amplifier, with FM processing for quasi
parallelsound system.
TDA4445B:
Sound IF amplifier, with FM processing and AM
demodulator, for multi-standard sound TV appliances.
TDA4445Badditionnal:
Bistandardapplications(B/G and L)
No adjustmentofthe AMdemodulator
Low AMdistortion
TDA4445A
TDA4445B
SOUNDIF AMPLIFIER
DIP16
(Plastic Package)
ORDER CODE : TDA4445A - TDA4445B
PIN CONNECTIONS
NOT TOBE CONNECTED
IF AGC TIMECONSTANT
NOT TO BE CONNECTED
NOT TO BE CONNECTED FOR TDA4445A
AVERAGING CAPACITOR FOR TDA4445B
NOT TO BE CONNECTED FOR TDA4445A
A.F. SOUND OUTPUT FOR TDA4445B
NOT TOBE CONNECTED
REFERENCE L.C.NETWORK REFERENCE L.C. NETWORK
December 1992
IF INPUT
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
IF INPUT
NOT TO BE CONNECTED
NOT TO BE CONNECTED
GROUND
FM MODULATED SOUND OUTPUT
SUPPLY VOLTAGE
NOT TO BE CONNECTED
9
4445-01.EPS
1/6
TDA4445A - TDA4445B
BLOCK DIAGRAMS
TDA4445A
TDA4445B
GENERALDESCRIPTION
This circuit includesthe followingfunctions:
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Three symmetrical and gain controlled wide
band amplifier stages, which are extremely stable by quasiDC couplingwithoutfeedback.
.
AveragingAGCwith dischargecontrolcircuit
.
AGCvoltage generator
Quasi parallel sound operation:
.
High phase accuracy of the carriersignal proc-
essing,independentfrom AM
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Linearquadraturedemodulator
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Sound-IF-amplifier stage with impedance converter
AM-Demodulation (onlyTDA4445B) :
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Carriercontrolleddemodulator
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Audio frequency stage with impedance converter
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AveraginglowpassAGC
4445-02.EPS/ 4445-03.EPS
2/6
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