Rev 1.1, February 2, 2007

Page 9 of 13

SL23EP09

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 pins. 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 output clocks and

the load is over 1 ½ inch. The nominal impedance of the clock outputs is given on the page 4. Place the series termination

resistors 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 feedback to PLL, and

sees an additional 2 pF load with respect to Bank A and B clocks. 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 Bank A and B clocks and

CLKIN.

For minimum pin-to-pin skew, the external load at all the Bank A and B clocks must be the same.