TDA4445A Datasheet, PDF (2/8 Pages) STMicroelectronics – SOUND IF AMPLIFIER

TDA4445A/TDA4445B
TELEFUNKEN Semiconductors
Pin Description
Pin
1–16
3
8–9
11
12
13
2, 4,
7, 10,
14, 15
Symbol
Function
IF input
If AGC time constant
Tuned circuit
Supply voltage
Sound-IF-output
Ground
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 Sound–IF–amplifier stage with impedance converter
AM–Demodulation (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
Supply current
External voltages
TDA4445A, B
TDA4445B only
Pin 11
V_S
Pin 11
I_S
10 ... 15
V
70
mA
Pin 3
V_ext
12
V
Pin 12
8
Pin 5, 6
8
Power dissipation in soldered position
Junction temperature
Ambient temperature range
Storage temperature range
P_tot
1
W
T_j
125
°C
T_amb
–25 to +70
°C
T_stg
–25 to +125
°C
Thermal Resistance
Junction ambient
Parameters
Symbol
R_thJA
Value
60
Unit
K/W
2 (8)
Rev. A1: 14.09.1995