Rev 1.4, May 25, 2007

Page 7 of 11

SL2305

External Components & Design Considerations

Typical Application Schematic

Comments and Recommendations

Decoupling Capacitor: A decoupling capacitor of 0.1 F must be used between VDD and VSS on the pins 6 and 4. Place

the capacitor on the component side of the PCB as close to the VDD pin as possible. The PCB trace to the VDD pin and to

the GND via should be kept as short as possible. Do not use vias between the decoupling capacitor and the VDD pin.

Series Termination Resistor: A series termination resistor is recommended if the distance between the outputs and the

load is over 1 ½ inch. The nominal impedance of the Clock outputs are about 30

. Use 20

resistor in series with the

output to terminate 50

trace impedance and place 20

resistor as close to the clock outputs as possible.

Zero Delay and Skew Control: All outputs and CLKIN pins should be loaded with the same load to achieve “Zero Delay”

between the CLKIN and the outputs. The CLKOUT pin is connected to CLKIN internally on-chip for internal feedback to

PLL, and sees an additional 2 pF load with respect to the clock pins. For applications requiring zero input/output delay, the

load at the all output pins including the CLKOUT pin must be the same. If any delay adjustment is required, the capacitance

at the CLKOUT pin could be increased or decreased to increase or decrease the delay between clocks and CLKIN.

For minimum pin-to-pin skew, the external load at the clock outputs must be the same.