Functional Description
FM-IF amplifier, consisting in a limiter amplifier with FM demodulator. The AF section contains a
SCART-record/playback switch as well as AF output with volume control. The control of the volume
is controlled via an analog control input, and the SCART switch is controlled via a switch input.
Application
Application of the IC is intended in mono TV sets.
Circuit Description
In its FM section, the component contains an eight stage, symmetrical limiter amplifier with
subsequent coincidence demodulator. The AF section contains an analog switch for the SCART-
recording / playback function as well as an analog volume control with AF output.
Type
Ordering Code
Package
TBA 121-5
Q67000-A5137
P-DIP-16
FM-Sound IF with SCART Switch
and Volume Control
Bipolar IC
P-DIP-16
Features
q
Outstanding limiting qualities
q
Few external components
q
Integrated de-emphasis resistor
q
Low harmonic distortion factor
Semiconductor Group
91
06.94
TBA 121-5
Semiconductor Group
92
TBA 121-5
Pin Functions
Pin No.
Function
1
Ground
2
Limiter amplifier operating point feedback
(RF decoupling of IF amplifier with appropriate capacitors is required!)
3
Limiter amplifier operating point feedback and low end
(RF decoupling of IF amplifier with appropriate capacitors is required!)
4
IF-amplifier output (emitter follower)
5
IF-amplifier output (emitter follower)
6
Demodulator input with high impedance input and internal 15 k
supply resistor
(if an
LC
circuit is used, the
Q
is determined by the damping resistance across
pins 6 and 7)
7
Demodulator input with high impedance input and internal 15 k
supply resistor
(if an
LC
circuit is used, the
Q
is determined by the damping resistance across
pins 6 and 7)
8
Connection for de-emphasis capacitor (a series resistor of 11 k
is integrated)
9
AF output of the SCART interface (emitter follower with short circuit limiter)
10
AF input 1 of the SCART interface (IF branch)
11
Rec/Pb switch input
12
AF input 2 of the SCART interface (SCART input)
13
Volume control
14
IF output (emitter follower)
15
+
V
S
supply voltage
16
IF input (limiter amplifier input; internal resistor between pin 16 and 3 typ. 800
)
Semiconductor Group
93
TBA 121-5
Expanded Block Diagram, Part 1
Semiconductor Group
94
TBA 121-5
Expanded Block Diagram, Part 2
Semiconductor Group
95
TBA 121-5
Block Diagram
Semiconductor Group
96
TBA 121-5
Absolute Maximum Ratings
T
A
= 0 to 70 C
Parameter
Symbol
Limit Values
Unit
min.
max.
Supply voltage
V
S
0
16
V
IF-input voltage
V
I 16 rms
0
600
mVrms
DC voltage
DC voltage
DC voltage
DC voltage
DC voltage
DC voltage
DC voltage
DC voltage
DC voltage
DC voltage
V
2
V
3
V
6
V
7
V
8
V
9
V
11
V
12
V
13
V
16
0
0
0
0
0
0
0
0
0
0
V
REF
V
REF
V
S
V
S
V
S
-2
V
REF
V
S
V
S
V
S
V
REF
V
V
V
V
V
V
V
V
V
V
DC current
DC current
DC current
DC current
I
4
I
5
I
9
I
14
0
0
1
1
2
2
2
2
mA
mA
mA
mA
Junction temperature
T
j
150
C
Storage temperature
T
stg
55
125
C
Thermal resistance
(system-air)
R
th SA
80
K/W
Operating Range
Supply voltage
V
S
10.5
15.75
V
Frequency range
f
0.1
12
MHz
Ambient temperature in operation
T
A
0
70
C
Semiconductor Group
97
TBA 121-5
Characteristics
T
A
= 0 to 70 C;
V
S
= 10.5 to 15.5 V; refer to test circuit
Parameter
Symbol
Limit Values
Unit
Test Condition
min.
typ.
max.
Current consumption
I
S
21
29
37
mA
Input voltage for
limiting response
(
V
Q 9, 14
= 3 dB)
V
I 16 rms
60
100
V
f
I 16
= 5.5 MHz;
f
= 30 kHz;
f
mod
= 1 kHz
SCART-output voltage
V
Q 9
500
650
mV
V
I 16
= 10 mV;
f
= 30 kHz;
f
mod
= 1kHz
f
I 16
= 5.5 MHz
AF-output voltage
V
Q 14
450
650
mV
V
13
= 4.8 V;
f
= 30 kHz;
f
mod
= 1 kHz;
f
I 16
= 5.5 MHz
DC component
V
Q 9
V
Q 14
4.8
6
V
V
V
I 16
= 10 mV;
f
= 0
THD
=
THD
min
Total distortion factor
THD
9
THD
14
1
1.1
%
%
f
= 30 kHz;
V
I 16
= 10 mV;
f
mod
= 1 kHz
f
I 16
= 5.5 MHz
V
13
= 4.8 V
AM suppression
(test conditions for
reference point)
a
AM9, 14
50
60
dB
V
I 16
= 500
V;
m
= 30%;
f
mod
= 1 kHz;
f
I 16
= 5.5 MHz;
f
= 30 kHz;
V
I 16
= 10 mV
Volume control range
V
14
80
dB
V
13
= 5-0 V
Maximum SCART-
input voltage
V
I 12
2
Vrms
Gain between SCART
input (pin 10) and
AF output (pin 14)
G
SC
0
dB
V
11
8 V
12 V
V
13
= 4.8 V
Switching Voltage, Muting
ON (AF OFF)
OFF
V
3
V
3
8
0
V
S
3
V
V
Semiconductor Group
98
TBA 121-5
Characteristics (cont'd)
T
A
= 0 to 70 C;
V
S
= 10.5 to 15.5 V; refer to test circuit
Parameter
Symbol
Limit Values
Unit
Test Condition
min.
typ.
max.
Design Notes
Input resistance
R
I 6, 7
10
k
Output resistance
R
Q 9
100
Output resistance
R
Q 14
200
Input resistance
R
I 10, 12
20
k
Input impedance
Z
I 16
800
Residual IF voltage
V
Q 9, 14 (IF)
10
mV
Hum suppression
V
S
/
V
Q 9, 14
(without
de-emphasis
C
)
a
qh
30
dB
V
S
= 500 mVrms
f
S
= 100 Hz
Crosstalk attenuation
(test conditions for
reference point)
a
12-14
60
dB
V
12
= 2 Vrms;
RF mode:
f
= 30 kHz;
f
mod
= 1 kHz;
f
I 16
= 5.5 MHz
V
I 16
= 10 mV
Attenuation IF MUTE
a
14
80
dB
f
I 16
= 5.5 MHz;
V
13
= 4.8 V;
V
I 16
= 300
mV;
f
mod
= 1 kHz;
f
= 30 kHz;
IF MUTE = ON;
measured
selectively
at 1 kHz
Semiconductor Group
99
TBA 121-5
Test Circuit
Semiconductor Group
100
TBA 121-5
Application Circuit
Volume
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