vpx3224d ETC-unknow, vpx3224d Datasheet - Page 53

• Manufacturer Part Number: vpx3224d
• Description: Video Pixel Decoders
• Manufacturer: ETC-unknow

Micronas
PRELIMINARY DATA SHEET
4.2.4. Recommended Crystal Characteristics
Symbol
T
f
Df
Df
R
C
C
Load Capacitance Recommendation
C
DCO Characteristics
C
C
1)
External capacitors at each crystal pin to ground are required. They are necessary to tune the effective load
capacitance of the PCBs to the required load capacitance (C
lower the clock frequency results. The nominal free running frequency should match f
different layouts of customer PCBs, the matching capacitor size should be determined in the application. The
suggested value is a figure based on experience with various PCB layouts.
Tuning condition: Code DVCO Register = –720
2)
The pulling range of the DCO is a function of the used crystal and effective load capacitance of the IC (C
+ C
f
3)
The DCO hardware register has 8 bits; the FP control register uses a range of –2048...2047.
P
L
A
R
0
1
Lext
ICLoadmin
ICLoadrng
P
P
Remarks on defining the External Load Capacitance:
Remarks on Pulling Range of DCO:
= f
Remarks on DCO Codes:
/f
/f
LoadBoard
P
P
P
* –––––––––––––––––––––––
1 + 0.5 * [ C
1 + 0.5 * [ C
). The resulting frequency (f
Parameter
Operating Ambient Temperature
Parallel Resonance Frequency
with Load Capacitance C
Accuracy of Adjustment
Frequency Temperature Drift
Series Resistance
Shunt Capacitance
Motional Capacitance
External Load Capacitance
pins to Ground (PLCC44)
(pin names: Xtal1 Xtal2)
Effective Load Capacitance @ min.
DCO-Position, Code 0,
package: PLCC44
Effective Load Capacitance Range,
DCO Codes from 0..255
2)
1
1
/ (C
/ (C
0
0
+ C
+ C
L
Leff
) ]
) ]
L
) with an effective load capacitance of C
L
= 13 pF
1)
from
Min.
0
–
–
–
–
3
20
–
3
8.7
L
) of the crystal. The higher the capacitors, the
VPX 3225D, VPX 3224D
Typ.
–
20.250000
fundamental
–
–
–
–
–
4.7
4.3
12.7
Leff
= C
p
= 20.25 MHz. Due to
ICLoad
Max.
65
–
25
7
30
–
5.5
16.7
20
30
+ C
LoadBoard
ICLoad
Unit
MHz
ppm
ppm
W
pF
fF
pF
pF
pF
C
is
53