NTE NTE875 Datasheet
NTE875
Integrated Circuit
Video IF Amplifier/PLL Detector System
Description:
The NTE875 is a complete video IF signal processing system on a single 28–Lead DIP type package.
This device contains a 5–stage gain–controlled IF amplifier, a PLL synchronous amplitude detector,
self–contained gated AGC, and a switchable AFC detector. The increased flexibility of the NTE875
makes it suitable for a wide variety of television applications where high quality video or sound carier
recovery is required. These include home receiver video IFs, cable and subscription TV decoders,
and parallel sound IF/intercarrier detector systems. Typical operating frequencies are 38.9MHz,
45.75MHz, 58.75MHz, and 61.25MHz.
Features:
D Low Differential Gain and Phase
D IF and Detector pin Compatible with NTE878 (Discontinued)
D Common–Base IF Inputs for SAW Filters
D True Synchronous Video Detector using PLL (Phase Lock Loop)
D Excellent Stability at High System Gains
D Noise–Average Gated AGC System
D Uncommitted AGC Comparator Input
D Internal AGC Gate Generator
D Superior Small–Signal Detector Linearity
D AFC Detector with Adjustable Output Bias
D 9MHz Video Bandwidth
D Reverse Tuner AGC Output
Absolute Maximum Ratings:
Power Supply Voltage, V
IF Supply Current, I
AGC Gate Voltage, V
Video Output Current, I
Phase Lock Loop (PLL) Filter Current, I
Detector Input Signal, ν
Power Dissipation, P
Thermal Resistance, Junction–to–Ambient, R
Junction Temperature, T
Operating Temperature Range, T
Storage Temperature Range, T
2
5
14
16
18
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DET
D
thJA
J
opr
stg
Lead Temperature (During Soldering, 10sec), T
15V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
60mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±5V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1V
rms
2W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
50°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
+125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0°C to +70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
–65°C to +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
L
+260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC Electrical Characteristics: (TA = +25°C, VIF = ν
switches in position 0 (open) unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
= 0, VPH = 4V, V
DET
= 4V, and all
COMP
12V Supply Current I1 + I2V
IF Regulator Voltage V
5
IF Input Voltage V7, V8V
IF Decouple Offset V6 – V9V
IF Peaker Voltage (Max Gain) V3, V4V
IF Output Current I
1
IF Peaker Voltage (Min Gain) V3, V4V
Detector Input Voltage V
28
Limiter Tank Voltage V24, V25V
AFC Tank Voltage V23, V26V
VCO Tank Voltage V19, V20V
AGC Sync Threshold V
AGC Filter Leakage Current I
AGC Filter Charge Current I
AGC Filter Discharge Current I
RF AGC Leakage Current I
RF AGC Output Current I
17
13
13
13
11
11
= 6.7V, V
AGC
V
= 6.7V, SW4 Position 1 5.8 6.4 7.0 V
AGC
= 2V, SW2, 3, 4 Position 1 3.2 3.7 4.1 V
AGC
= 2V, SW2, 3, 4 Position 1 – 0 ±30 mV
AGC
= 2V, SW2, 3, 4 Position 1 2.3 3.0 3.6 V
AGC
V
= 9V, SW2, 3, 4 Position 1,
AGC
Measure V
= 9V, SW2, 3, 4 Position 1 5.5 6.2 – V
AGC
V
= 6.7V, SW1, 4 Position 1 4.3 4.9 5.5 V
AGC
= 6.7V, SW1, 4 Position 1 6.4 7.0 7.6 V
AGC
= 6.7V, SW1, 4 Position 1 4.3 4.9 5.5 V
AGC
= 6.7V, SW1, 4 Position 1 4.7 5.2 5.7 V
AGC
, I1 = (12 – V1)/50
1
SW1, 2 Position 1, Adjust V
= 0
I
13
= 6V 35 60 80 mA
COMP
3.1 5.5 7.8 mA
COMP
for
3.8 4.0 4.2 V
SW1, 2, 4 Position 1 – 0 ±5 µA
SW1, 2 Position 1, V
SW1, 2 Position 1, V
V
= 2V, All Switches Position 1,
AGC
Measure V
V
= 10V, All Switches Position 1,
AGC
Measure V
, I11 = (12 – V11)/6000
11
, I11 = (12 – V11)/6000
11
= 3.5V 1.6 2.2 2.8 mA
COMP
= 4.5V –0.45 –0.70 –0.90 mA
COMP
– 0 20 µA
1.5 1.8 – mA
Detector AC Set–Up Procedure: (SW1, 4 position 1, V
1. Apply ν
DET
= 10mV
, 45.75MHz CW at the detector input. Tune L1 for maximum AC signal
rms
at Pin25, measured with a 10x FET probe or through a 1pF capacitor to prevent loading of
the limiter tank.
2. Increase ν
to 60mV
DET
. Adjust L3 until the PLL locks, as indicated by a DC voltage at
rms
the video output Pin16.
3. With the detector locked, adjust L3 for 4V at Pin18.
4. Adjust V
for maximum detector efficiency by monitoring Pin16 for a minimum DC voltage.
PH
5. Adjust L2 for 3.0V at Pin27 (on sensitive slope of AFC curve).
AC Electrical Characteristics:
(TA = +25°C, Detector set–up as above, f = 45.75MHz,
V
= 6.7V, V
AGC
= 4V, and allswitches in position 0 (open)
COMP
unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
IF Amplifier Gain ν
V
for 15dB Gain Reduction SW2, 3, 4 Position 1, νIF = 2.8mV
AGC
V
for 45dB Gain Reduction SW2, 3, 4 Position 1, νIF = 89mV
AGC
OUT/νIFVAGC
= 2V, SW2, 3, 4 Position 1,
ν
= 500µV
IF
Adjust V
, Note 1
rms
for Same ν
AGC
Test
Adjust V
for Same ν
AGC
Test
AGC
= 0V)
OUT
OUT
as Gain
rms
as Gain
rms
25 35 – dB
,
4.2 4.6 5.0 V
,
5.1 5.5 6.1 V
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