
MC13001X MC13007X
7
MOTOROLA ANALOG IC DEVICE DATA
The period during which sync can reset the counter and
cause flyback is determined by the window control which
defines a count range during which the gate is open. One of
two ranges is selected according to the condition of the
signal. The normal “narrow” range is 514 to 526 counts for a
525 line system and is selected after the coincidence
detector indicates that the reset is coincident, twice in
succession, with the 525 count from the counter. When the
detector indicates non–coincidence 8 times in succession,
then the window control switches to the “wide” mode (384 to
544 counts) to achieve rapid re–synchronization. For the 625
line version the counts are 614 to 626 for narrow mode and
484 to 644 for wide mode. Note that the OR gate after the
sync gate is used to terminate the count at the end of the
respective window if a sync pulse has not appeared.
This method accepts nonstandard signals almost in the
same way as a conventional triggered RC oscillator and has
a similar fast lock–in time. However, the use of a window
control on the counter reset ensures that when locked with a
normal standard broadcast signal the counter will reject most
spurious noise pulse.
The blanking output is provided from a latch which is set by
the counter reset pulse and terminated by count 20 from the
counter chain.
7.0 V
6.0 V
–2.5 V
2.0 V
0 V
–4.0 V
500 mV pp
1.0 V pp
23
20
22
21
Figure 10. Vertical Waveforms
Power Supply
The power supply regulator, although of simple design,
provides two independent power supplies – one for the
horizontal PLL section and the other for the remainder of the
chip. The supplies share the same reference voltage but
the design of the main regulator is such that it can be
switched on independently to give minimum loading on the
“bleed” voltage source during startup phase of a
defection–derived supply system.
+ VBL
RBL =
VBL – 8
4 x 10–3
Horizontal
Startup Bleed
Main
12 V Supply
IEXT
8.2 V to
External
Circuits
R6
RBL
18
19
8.2V to
All Monomax
Circuits Except
Horizontal
8.2 V to
Horizontal
System
R1
Q6
D1
Z1
Q7
Q1
Q4
R5
R4
Q2
R3
Q3
R2
Q5
D2
Figure 11. Power Supply Circuit
IEXT (mA)
< 5.0
R6 (
)
150
20
82
35
68