ICS8422002I-01

FEMTOCLOCKS™ CRYSTAL-TO-LVHSTL FREQUENCY SYNTHESIZER

PRELIMINARY

IDT™ / ICS™ LVHSTL FREQUENCY SYNTHESIZER

8

ICS8422002AGI-01 REV. C NOVEMBER 1, 2007

Application Information

Power Supply Filtering Technique

As in any high speed analog circuitry, the power supply pins are

vulnerable to random noise. To achieve optimum jitter

performance, power supply isolation is required. The

ICS8422002I-01 provides separate power supplies to isolate any

supply plane through vias, and 0.01µF bypass capacitors should

along with a 10

µF bypass capacitor be connected to the V

Figure 1. Power Supply Filtering

Recommendations for Unused Input and Output Pins

Inputs:

LVCMOS Control Pins

All control pins have internal pull-ups or pull-downs; additional

resistance is not required but can be added for additional

protection. A 1k

Ω resistor can be used.

For applications not requiring the use of the crystal oscillator input,

both XTAL_IN and XTAL_OUT can be left floating. Though not

required, but for additional protection, a 1k

Ω resistor can be tied

from XTAL_IN to ground.

For applications not requiring the use of the reference clock, it can

be left floating. Though not required, but for additional protection,

a 1k

Ω resistor can be tied from the REF_CLK to ground.

Outputs:

LVHSTL Outputs

All unused LVHSTL outputs can be left floating. We recommend

that there is no trace attached. Both sides of the differential output

pair should either be left floating or terminated.

3.3V

10

Ω

10µF

.01µF

.01µF