NTE NTE788

NTE788
Integrated Circuit
IF System for FM Receiver
Description:
The NTE788 is a monolithic integrated circuit in a 16–Lead DIP type package that provides all the
functions of a comprehensive FM–IF system. This device features a three–stage FM–IF amplifier/limiter configuration with level detectors for each stage, a doubly–balanced quadrature FM detector, and
an audio amplifier that features the optional use of a muting (squelch) circuit.
The advanced circuit design of the IF system includes desirable deluxe features such as delayed AGC
for the RF tuner, an AFC drive circuit, and an output signal to drive a tuning meter and/or provide stereo switching logic. In addition, internal power supply regulators maintain a nearly constant current
drain over the voltage supply range of +8.5V to +16V.
Features:
D Exceptional limiting sensitivity: 12µV typ. at –3dB point
D Low distortion: 0.1% typ. (with double–tuned coil)
D Single–coil tuning capability
D Improved S + N/N Radio
D Externally programmable recovered audio level
D Provides specific signal for control of interchannel muting (squelch)
D On channel step for search control
D Provides programmable AGC voltage for RF amplifier
D Internal supply–voltage regulators
D Externally programmable “ON” channel step width, and deviation at which muting occurs
Absolute Maximum Ratings: (TA = +25°C unless otherwise specified)
DC Supply Voltage
Between Pin11 and Pin4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16V
Between Pin11 and Pin14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16V
DC Current (Out of Pin15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2mA
Power Dissipation (Up to TA = 85°C), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640mW
Derate Above TA = +85°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.9mW/°C
Operating Ambient Temperature Range, Topr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40° to +85°C
Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65° to +150°C
Lead Temperature (During Soldering, 1.32” from case, 10sec max), TL . . . . . . . . . . . . . . . . . +265°C
Electrical Characteristics: (TA = +25°C, V+ = 12V unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
20
31
40
mA
Static Characteristics
Quiescent Circuit Current
I11
DC Voltages
IF Input
V1
1.2
1.9
2.4
V
AC Return to Input
V2
1.2
1.9
2.4
V
DC Bias to Input
V3
1.2
1.9
2.4
V
RF AGC
V15
7.5
9.5
11.0
V
DC Reference
V10
5.0
5.6
6.0
V
–
12
25
µV
45
55
–
dB
300
400
500
mV
–
0.5
1.0
%
–
0.1
–
%
60
67
–
dB
No Signal Input, Non Muted
Dynamic Characteristics (fO = 10.7MHz, fmod = 400Hz, Deviation = ±75kHz)
Input Limiting Voltage
AM Rejection
Recovered AF Voltage
Total Harmonic Distortion
Single Tuned
V1 (lim) –3dB Point
AMR
VIN = 0.1V, AM Mod = 30%
VO (AF) VIN = 0.1V
THD
VIN = 0.1V, Note 1
Double Tuned
Signal Plus Signal–to–Noise Ratio
VIN = 0.1V
Note 1. THD characteristics are essentially a function of the phase characteristics of the network
connected between Pin8, Pin9, and Pin10.
Pin Connection Diagram
IF Input
1
16 N.C.
Decouple
2
15 AGC
IF Bias
3
14 GND
IF GND
4
13 Tuning Meter
Mute Input
5
12 Mute Logic
Audio Output
6
11 VCC
AFC Output
7
10 Ref Bias
IF Output
8
9
16
Quad Input
9
.260 (6.6) Max
1
8
.785 (19.9) Max
.300 (7.62)
.200 (5.08)
Max
.245
(6.22)
Min
.100 (2.54)
.700 (17.7)