MK3732-22
BLU-RAY DISC VCXO VCXO AND SYNTHESIZER
IDT™ / ICS™
BLU-RAY DISC VCXO 4
MK3732-22 REV D 020906
Where:
f
target
= nominal crystal frequency
error
xtal
=actual initial accuracy (in ppm) of the crystal being
measured
If the centering error is less than ±25 ppm, no adjustment is
needed. If the centering error is more than 25 ppm negative,
the PC board has excessive stray capacitance and a new
PCB layout should be considered to reduce stray
capacitance. (Alternately, the crystal may be re-specified to
a higher load capacitance. Contact ICS for details.) If the
centering error is more than 25 ppm positive, add identical
fixed centering capacitors from each crystal pin to ground.
The value for each of these caps (in pF) is given by:
External Capacitor =
2 x (centering error)/(trim sensitivity)
Trim sensitivity is a parameter which can be supplied by your
crystal vendor. If you do not know the value, assume it is 30
ppm/pF. After any changes, repeat the measurement to
verify that the remaining error is acceptably low (typically
less than ±25 ppm).
PCB Layout Recommendations
For optimum device performance and lowest output phase
noise, the following guidelines should be observed.
1) The 0.01µF decoupling capacitors should be mounted on
the component side of the board as close to the VDD pins
as possible. No vias should be used between the
decoupling capacitors and VDD pins. The PCB trace to VDD
pin should be kept as short as possible, as should the PCB
trace to the ground via.
2) The external crystal should be mounted just next to the
device with short traces. The X1 and X2 traces should not
be routed next to each other with minimum spaces, instead
they should be separated and away from other traces.
3) To minimize EMI, the 33Ω series termination resistor (if
needed) should be placed close to the clock output.
4) An optimum layout is one with all components on the
same side of the board, minimizing vias through other signal
layers. Other signal traces should be routed away from the
MK3732-22. This includes signal traces just underneath the
device, or on layers adjacent to the ground plane layer used
by the device.
Absolute Maximum Ratings
Stresses above the ratings listed below can cause permanent damage to the MK3732-22. These ratings, which are
standard values for ICS commercially rated parts, are stress ratings only. Functional operation of the device at
these or any other conditions above those indicated in the operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical
parameters are guaranteed only over the recommended operating temperature range.
Parameter Condition Min. Typ. Max. Units
Supply Voltage, VDD Referenced to GND 7 V
Inputs Referenced to GND -0.5 VDD+ 0.5 V
Clock Outputs Referenced to GND -0.5 VDD+ 0.5 V
Storage Temperature -65 150 °C
Soldering Temperature Max 10 seconds 260 °C
Junction Temperature 125 °C
