mk2069-01 Integrated Device Technology, mk2069-01 Datasheet - Page 8

• Manufacturer Part Number: mk2069-01
• Description: Vcxo-based Line Card Clock Synchronizer
• Manufacturer: Integrated Device Technology

Graph of Charge Pump Current vs. Value of R
Charge Pump Current, Example Settings from
Notes on Setting Charge Pump Current
The recommended range for the charge pump current is 25
µA to 300 µA. Below 25 µA, loop filter charge leakage, due
to PCB or capacitor leakage, can become a problem. This
loop filter leakage can cause locking problems, output clock
cycle slips, or low frequency phase noise.
As can be seen in the loop bandwidth and damping factor
equations or by using the filter response software available
from ICS, increasing charge pump current (I
both bandwidth and damping factor.
IDT™ / ICS™ VCXO-BASED LINE CARD CLOCK SYNCHRONIZER
MK2069-01
VCXO-BASED LINE CARD CLOCK SYNCHRONIZER
480 kΩ
400 kΩ
Above Graph
2 MΩ
1 MΩ
5 MΩ
3 MΩ
R
SET
Charge Pump Current
100E-6
10E-6
1E-3
100E+3
125 µA
255 µA
300 µA
25 µA
42 µA
65 µA
(I
CP
)
CP
) increases
R
SET
SET
1E+6
, ohms
8
VCXO Gain (K
(external resistor)
6 0 0 0
5 0 0 0
4 0 0 0
3 0 0 0
2 0 0 0
1 0 0 0
Recommended Range
O
of Operation
) vs. XTAL Frequency
1 0
C ry s ta l F re q u e n c y , M H z
1 5
VCXO AND SYNTHESIZER
10E+6
2 0
MK2069-01
2 5
REV H 050203
3 0