ICS84427CMLF datasheet(7/16 Pages) IDT

No. de pieza	ICS84427CMLF

Descripción Electrónicos	Crystal-to-LVDS Integrated Frequency Synthesizer/Fanout Buffer

PDF	16 Pages

Scroll/Zoom	100%

Fabricante Electrónico	IDT [Integrated Device Technology]

Página de inicio	http://www.idt.com

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7 / 16 page

REVISION B 5/6/15

84427 DATA SHEET

CRYSTAL-TO-LVDS

INTEGRATED FREQUENCY SYNTHESIZER/FANOUT BUFFER

APPLICATION INFORMATION

As in any high speed analog circuitry, the power supply

pins are vulnerable to random noise. The 84427 provides

separate power supplies to isolate any high switching

noise from the outputs to the internal PLL.V

DD and VDDA should be

individually 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 24

Ω resistor along with a 10μF and a

.01

μF bypass capacitor should be connected to each V

DDA pin.

POWER SUPPLY FILTERING TECHNIQUES

FIGURE 1. POWER SUPPLY FILTERING

DDA

μF

.01

μF

3.3V

.01

μF

CRYSTAL INPUT INTERFACE

The 84427 has been characterized with 18pF parallel resonant

crystals. The capacitor values, C1 and C2, shown in Figure 2

below were determined using an 18pF parallel resonant crystal

Figure 2. CRYSTAL INPUt INTERFACE

and were chosen to minimize the ppm error. The optimum C1

and C2 values can be slightly adjusted for different board layouts.

18p

18pF Parallel Crystal

22p

XTAL_IN

XTAL_OUT

ICS84427CMLF Datasheet(PDF) 7 Page - Integrated Device Technology