ICS650-47 Datasheet, PDF (4/10 Pages) Integrated Circuit Systems – Spread Spectrum Clock Synthesizer

P R E L I M I N A RY I N F O R M AT I O N
ICS650-47
Spread Spectrum Clock Synthesizer
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 pin as possible. No vias should be used
between the decoupling capacitors and VDD pins. The
PCB trace to VDD pins 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 ICS650-47. 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 ICS650-47. 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.
Item
Supply Voltage, VDD
All Inputs and Outputs
Ambient Operating Temperature
Storage Temperature
Junction Temperature
Soldering Temperature (max. of 10 seconds)
Rating
5V
-0.5 V to VDD+0.5 V
0 to +85°C
-65 to +150°C
125°C
260°C
Recommended Operation Conditions
Parameter
Ambient Operating Temperature
Power Supply Voltage (measured in respect to GND)
Power Supply Voltage (VDDO)
Power Supply Ramp Time, Figure 4
Min.
0
+3.135
+2.375
Typ.
+3.3
+2.5
Max.
+85
+3.465
+2.625
4
Units
°C
V
V
ms
MDS 650-47 B
4
Revision 082305
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