ICS845204

CRYSTAL-TO-MLVDS CLOCK SYNTHESIZER W/SPREAD SPECTRUM

ADVANCE INFORMATION

IDT™ / ICS™ M-LVDS CLOCK SYNTHESIZER

7

ICS845204AK SEPTEMBER 25, 2007

Parameter Measurement Information, continued

Offset Voltage Setup

Differential Output Voltage Setup

Application Information

Power Supply Filtering Technique

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

vulnerable to random noise. The ICS845204 provides separate

power supplies to isolate any high switching noise from the outputs

connected to the power supply plane through vias, and bypass

capacitors should be used for each pin. To achieve optimum jitter

performance, power supply isolation is required. Figure 1

illustrates how a 10

Ω resistor along with a 10µF and a 0.01µF

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.

Outputs:

M-LVDS Outputs

All unused M-LVDS output pairs can be either left floating or

terminated with 100

Ω across. If they are left floating, there should

be no trace attached.

out

out

M-LVDS

DC Input

➤

V

DD

➤

100

out

out

M-LVDS

DC Input

V

DD

100

3.3V

10

Ω

10µF

.01µF

.01µF