NTE NTE722

NTE722
Integrated Circuit
FM Stereo Multiplex Decoder
Description:
The NTE722 is a monolithic FM Stereo Multiplex Decoder System in a 14–Lead DIP type package.
This integrated circuit demodulated a stereo multiplex signal into the right and left audio channels
while inherently suppressing SCA frequency components. Internal provision is made for driving an
external stereo mode indicator lamp. The excellent performance and wide supply range requirement
make the NTE722 suitable for all line–operated and automotive FM stereo multiplex applications.
Features:
D 45dB Channel Separation
D 55dB Storcast Rejection without SCA Filters
D High Current Stereo Indicator Lamp Driver
D Operation with 8V to 14V Supplies
Absolute Maximum Ratings:
Supply Voltage (Note 1), V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V
Voltage at Stereo Lamp Driver Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22V
Current into Stereo Lamp Driver Terminal (Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100mA
Internal Power Dissipation, PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 670mW
Operating Temperature Range, Topr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +70°C
Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55° to +125°C
Lead Temperature (During Soldering, 10sec max), TL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +260°C
Note 1. Power supply transients up to 22V are permissible for periods of 15 seconds. However, extended operation at voltages greater than 15V should be avoided as the maximum allowable
internal power dissipation for this device may be exceeded.
Note 2. Rating applies to steady state current. Maximum permissible surge current during turn–on
of the Stereo Indicator Lamp is 500mA.
Electrical Characteristics: (TA = +25°C V+ = 12V, 200mVRMS standard stereo multiplex signal
applied to input, Note 3 unless otherwise specified)
Parameter
Test Conditions
Min
Typ
Max
Unit
Supply Current
–
12
18
mA
Input Resistance
12
20
–
kΩ
f = 100Hz
–
40
–
dB
f = 1kHz
30
45
–
dB
f = 10kHz
20
40
–
dB
Channel Balance (Monaural Input)
–
0.2
–
dB
Total Harmonic Distortion
–
0.5
1.0
%
Voltage Gain
–
1.0
–
V/V
Stereo Separation
67kHz Storecast Rejection
Note 4
–
55
–
dB
19kHz Pilot Level Required at Input
Stereo Indicator Lamp ON
–
12
22
mVRMS
Stereo Indicator Lamp OFF
4.0
8.0
–
mVRMS
19kHz
–
30
–
dB
38kHz
–
25
–
dB
High Frequency Audio Components
in Left and Right Outputs
(dB Below 1kHz Output)
Note 3. “Standard Stereo Multiplex Signal” here refers to a 200mVRMS (0.56VP–P) composite stereo
signal including 10% pilot with L = 1 and R = 1 as described in the FCC Rules of FM Broadcasting.
Note 4. Measured with a stereo composite signal consisting of 80% stereo, 10% pilot and 10% SCA
as defined in the FCC Rules on FM Broadcasting.
14
8
1
7
Pin Connection Diagram
19kHz Filter
1
14 Decoupling
19kHz Filter
2
13 38kHz Filter
MPX Input
3
12 Right Output
N.C.
4
11 Left Output
N.C.
5
10 38kHz Filter Bias
Stereo Lamp
6
9
V+
GND
7
8
N.C.
.785 (19.95)
Max
.300 (7.62)
.200 (5.08)
Max
.100 (2.45)
.600 (15.24)
.099 (2.5) Min