NTE742
Integrated Circuit
TV Sound Channel, 2W
Description:
The NTE742 is designed for use as the entire sound function in television receivers or FM table radios.
The NTE742 sound channel will directly drive a 16 ohm speaker with more than 2 watts output. This
monolithic integrated circuit will operate from a single 18V to 28V power supply and can also function
(with reduced power output) with supplies as low as 12V if additional decoupling is provided.
The NTE742 is supplied in an improved 16lead plastic dual inline package with heatsink contact
tabs. A copper alloy lead frame allows maximum power dissipation with standard cooling methods.
The unique lead configuration allows easy attachment of a heat sink and yet permits the use of a stan-
dard IC socket or printed wiring board layout.
Features:
D
Low limiting Threshold
D
Low External Parts Count
D
Wide Operating Voltage Range
D
70dB Limiter Gain
D
Automatic Thermal Shutdown
D
Output Current Limiting
D
Ripple Rejection Greater Than 20dB
Absolute Maximum Ratings:
Supply Voltage, V
CC
+28V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regulator Output Current, I
REG
10mA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Voltage (Pin 10), V
IN
+4.0V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Temperature Range, T
A
40
to +85
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage Temperature Range, T
S
65
to +150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Static Electrical Characteristics: (T
A
= +25
C, V
CC
= 24V unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Quiescent Supply Current
I
CC
V
IN
= 0
25
45
60
mA
Terminal Voltage
V
2
V
IN
= 0
10
V
V
3
2.6
V
V
OUT
12
V
V
REG
14
15
16
V
V
IN
1.4
V
V
14
, V
15
4
V
V
16
8
V
Dynamic Electrical Characteristics:
(T
A
= +25
C, V
CC
= 24V, f
o
= 4.5MHz, f
m
= 400Hz,
f = 25kHz, V
IN
= 10mV unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Input Limiting Threshold
V
TH
Note 1
150
400
V
AM Rejection
AMR
Note 2
30
> 50
dB
Recovered Audio
V
OUT
500
700
900
mV
Total Harmonic Distortion
THD
Test Pin16
< 1
3
%
Test Pin6, P
OUT
= 2W
2.5
10
%
Volume Control Voltage
V
1
3dB, Note 3
6.0
7.5
10
V
20dB, Note 3
2.0
2.8
4.0
V
40dB, Note 3
0.75
1.2
1.8
V
Playthrough
V
1
= 0V
5
25
mV
Power Amp Voltage Gain
A
e
V
OUT
= 1V
25
27
29
dB
Output Current Limiting
I
OUT
R
L
= 0
800
mA
Output Tracking
V
OUT
/V
CC
V
CC
= 18V to 27V
0.5
V/V
Output Noise
e
n
V
IN
= 0V, V
1
= 10V
5
25
mV
Power Amp Impedance
Z
in
f = 1kHz
50
k
Note 1. Adjust V
1
for V
OUT
= 2V, then reduce V
IN
until V
OUT
= 1.4V (3dB).
Note 2. Adjust V
1
for V
OUT
= 2V.
Note 3. Reference is V
OUT
at Pin 6 with V
1
= 12V.
Pin Connection Diagran
F
V
CC
Phase Shift
IF Input
LowLevel GND
1
2
3
F
DC Volume Control
Detector Output
Amplifier Input
GND
6
Audio Output
7
8
Regulator Output
16
15
14
DeEmphasis
Phase Shift
GND
11
IF Decoupling
10
9
i
n
i
n
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