EL4585CS-T7 Intersil, EL4585CS-T7 Datasheet - Page 9

• Manufacturer Part Number: EL4585CS-T7
• Description: IC PLL VIDEO GP 36MHZ 16-SOIC
• Manufacturer: Intersil
• Type: Phase Lock Loop (PLL)r

Specifications of EL4585CS-T7

• Pll: Yes
• Input: Clock
• Output: CMOS, TTL
• Number Of Circuits: 1
• Ratio - Input:output: 3:1
• Differential - Input:output: No/No
• Frequency - Max: 36MHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 5V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Frequency-max: 36MHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

positive when EXT DIV lags H
will depend on VCO design or VCXO module selection.
Applications Information
Choosing External Components
F
C
C
then:
C
For our example, C
for fine tuning.) Examples for each frequency using the
internal divider is shown in Figure 8.
NOTE: Use shielded inductors for optimum performance.
1. To choose LC VCO components, first pick the desired
2. Choose a reasonable inductor value (1µ to 5µH works
3. Calculate C
4. From the varactor data sheet find C
5. C
6. Calculate C
OSC
FREQUENCY
T
T
1
=
=
=
LC VCO COMPONENT VALUES (APPROXIMATE) (Note)
operating frequency. For our example we will use
28.636MHz, with an H
well). We choose 3.3µH.
lock voltage. C
our example.
26.602
35.468
21.476
24.546
28.636
(MHz)
2
27.0
29.5
-------------------- -
4π
------------------------------------------------------------------------- -
(
------------------------------------------------------------------------- -
(
=
C
C
should be about 10C
2
1
2
---------------------- -
2π LC
1
C
F
C
2
V
2
1
L
)
)
+
–
=
C
C
(
(
T
C
T
1
C
2
1
---------------------------------------------------------------------- -
4π
FIGURE 8. TYPICAL LC VCO
. Since:
C
C
1
2
needed to produce F
C
C
T
2
2
V
1
C
C
(
V
T
=23pF for our SMV1204-12 for example.
28.636e6
=17pF. (A trim capacitor may be used
(µH)
)
V
)
V
3.3
3.3
2.7
2.2
4.7
3.9
3.3
L
+
–
1
(
(
C
C
T
SYNC
2
C
C
1
V
V
V
2
, so we choose C
SYNC
9
)
)
) 3.3e 6
(
frequency of 15.734kHz.
.) The resistance needed
(pF)
C
–
22
21
22
16
26
22
17
1
OSC
V
)
@ 2.5V, the desired
=
.
9.4pF
2
=220pF for
(pF)
220
220
220
220
220
220
220
C
2
(EQ. 1)
(EQ. 2)
(EQ. 3)
EL4585
Typical Application
Horizontal genlock provides clock for an analog-to-digital
converter, digitizing analog video.
The oscillators are arranged as Colpitts oscillators
(see Figure 8), and the structure is redrawn here to emphasize
the split capacitance used in a Colpitts oscillator. It should be
noted that this oscillator configuration is just one of literally
hundreds possible, and the configuration shown here does not
necessarily represent the best solution for all applications.
Crystal manufacturers are very informative sources on the
design and use of oscillators in a wide variety of applications,
and the reader is encouraged to become familiar with them.
FREQUENCY
26.602
35.468
21.476
24.546
28.636
(MHz)
27.0
29.5
XTAL VCO COMPONENT VALUES (APPROXIMATE)
FIGURE 9. TYPICAL XTAL VCO
(kΩ)
300
300
300
300
300
300
300
R
1
(pF)
C
15
15
15
15
15
15
15
1
September 3, 2009
0.001
0.001
0.001
0.001
0.001
0.001
0.001
(µF)
C
2
FN7175.4