MC44144 Datasheet, PDF (4/8 Pages) Motorola, Inc – SUBCARRIER PHASE–LOCKED LOOP

MC44144
PIN FUNCTION DESCRIPTION
Name
Pin
Representative Circuitry
Description
Expected Waveforms
Subcarrier
1
Output
VCC
Subcarrier Output. A
phase–locked reference of the
PAL or NTSC color burst is
output at this pin.
A 300 mVpp square wave is output.
Some high frequency content is
present.
200
5.0k
Ground
Phase
Detector
Output
4X Sub Xtal
2
Circuit Ground
3
The error current from the
A beat waveform, showing both
1.0k 31k
phase detector is output at this horizontal period and half the
pin. A filter circuit should be
subcarrier period, is present.
33k
2.5V
connected at this pin.
1/2 Subcarrier Period
Line Period
Vlock
4
Crystal Oscillator Pin. A 4X
Approximately 40 mVpp. A scope
VCC _{subcarrier parallel resonant}
probe will disturb the frequency of
400 ^gm
gm
crystal, in series with a 5.0 to
25 pF trimmer capacitor
oscillation.
Vref
provides the resonant element
for the Voltage Controlled
Crystal Oscillator (VCXO).
2.0k
4X Subcarrier
5
Output (or
Black Burst)
VCC
5.0k
Buffered output from the 4X
voltage controlled oscillator.
The sinusoidal 4Xfsc oscillator output
is available at this pin.
The output is nominally:
525 mVpp for NTSC,
425 mVpp for PAL.
Composite
6
Video Input
(Black Burst,
Continuous
Wave, or
Composite
Chroma
can also be
applied)
Burst Gate
7
Input
VCC
8
VCC
22k
VCC
22k
22k
Composite Video Input. Color
burst from the video present at
this pin is used as a reference
to phase lock the VCXO.
Positive or negative video may
be used.
Composite video should be applied
at this pin. The color burst
amplitude of the input video should
be at least 50 mV, but no more than
1000 mV. The waveform at this pin
should not exceed ground or VCC.
VCC
Input for the phase detector
gate pulse. TTL compatible.
The threshold is nominally
2.6V.
2.6V
GND
A positive going gate pulse should
be applied at this pin. The Burst Gate
input should envelope the color
burst.
Pin 6
Pin 7
2.2V
Power Supply Pin. 5.0 Vdc
should be applied at this pin.
4
MOTOROLA ANALOG IC DEVICE DATA