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Pin No.
17
18
19
PLL Filter (Main Loop) 19
20, 21
VCO Coil
22
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PIN FUNCTION DESCRIPTION (continued)
Equivalent Internal Circuit
V CC
17
Flyback/Video Input
0.02
From Negative Video
Output Pin 5
V CC
V CC
0 or 80 µA
Lock Detector/Filter
18
(Acquisition Circuit)
0.1
220
0.01
V CC
V CC
0 to 160 µA
22 k
V CC
560
L4
C19
C20
20
21
VCO Coil
V CC
4.7 k
MC44302A
Flyback/Video Input
V CC
This input connects to a positive going sync source to generate an
internal AGC keying pulse. An internal sync separator is provided
for use in stand alone applications where a horizontal scan signal
is unavailable. The sync separator allows direct use of the
negative video output at Pin 5 to set the internal keying pulse. If
horizontal scan circuitry is available, a positive going flyback pulse
can be used instead to set the keying pulse.
Lock Detector/Filter (Acquisition Circuit)
V CC
A filter capacitor for the acquisition circuit lock detector connects
from this pin to ground. The capacitor voltage will vary upon signal
3.3 V
presence and lock condition. Typical voltages are 2.7 V with the
68 k
circuit unlocked and without any signal, 0.8 V to 4.3 V during signal
5.0 k
acquisition, and 4.3 V when locked. Refer to the Acquisition Circuit
Timing in Figure 25.
PLL Filter (Main VCO Loop)
A filter capacitor for the main phase–locked loop circuit connects
0.1
from this pin to ground. The typical capacitor voltage is 3.2 V when
locked and the circuit has reached the final static condition. Refer
V CC
to Figure 5 for the PLL filter voltage versus carrier frequency
change, and to Figure 25 for the acquisition circuit timing.
3.9 V
VCO Coil
These are the voltage controlled oscillator pins. Symmetrical
tuning about the VCO frequency is provided by a bifiliar wound coil
that resonates at one half of the desired IF frequency. The coil
must be placed close to the IC pins to prevent any unwanted
pickup or radiation. The printed circuit board layout must have
short symmetrical traces with adequate grounding for the can
shield. Capacitors C19 and C20 should not be less than 33 pF.
Suggested component values for the major IF frequencies are
listed in Table 3.
V CC
4.7 k
Description
MOTOROLA ANALOG IC DEVICE DATA
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