NTE748
Integrated Circuit
TV Sound Circuit
Description:
The NTE748 is an integrated circuit in a 14–Lead DIP type pacjage designed for IF limiting, detection,
audio preamplifier and driver for the sound portion of a TV receiver.
Features:
D Excellent Limiting with 80µV(rms) Input Signal typ
D Large Output–Voltage Swing–to 3.5V(rms) typ
D High IF Voltage Gain–65dB typ
D Zener Power–Supply Regulation Built–in
D Short–Circuit Protection
D A Coincidence Discriminator that Requires Only One RLC Phase Shift Network
D Preamplifier to Drive a Single External–Transistor Class–A Audio Output Stage
Absolute Maximum Ratings: (TA = +25°C unless otherwise specified)
Power Supply Voltage, V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +16V
Input Voltage, Vin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.7V(rms)
Power Dissipation (Package Limitation), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625mW
Derate above +25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0mW/°C
Operating Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +75°C
Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65° to +150°C
Electrical Characteristics: (V+ = 12V, TA = +25°C, f = 4.5MHz, Deviation = ±25kHz unless
otherwise specified)
Parameter
Input Voltage
Symbol
Test Conditions
Min Typ Max Unit
V
L
–3dB Limiting
V = 20mV
–
–
80 160 µV
rms
AM Rejection
AMR
V : f = 4.5MHz,
OFM
45
–
dB
,
rms
in
Deviation = ±25kHz, Q = 24
AM = 30%,
L
AMR = 20 log,
Note 1
V
: f = 5.5MHz,
–
45
–
dB
OAM
Deviation = ±50kHz, Q = 30
L
Total Harmonic Distortion
THD
Q = 24, 7.5kHz Deviation, Note 1
–
–
1.0
3.5
–
–
%
L
Maximum Undistorted Audio
Output Voltage (Pin10)
V
o(max)
Audio Gain Adjusted Externally, Q = 24, Note 1
V
rms