IDT5V41066  
					4 OUTPUT PCIE GEN1/2 SYNTHESIZER  
					Application Information  
					Decoupling Capacitors  
					Load Resistors RL  
					As with any high-performance mixed-signal IC, the  
					IDT5V41066 must be isolated from system power supply  
					noise to perform optimally.  
					Since the clock outputs are open source outputs, 50 ohm  
					external resistors to ground are to be connected at each  
					clock output.  
					Decoupling capacitors of 0.01µF must be connected  
					between each VDD and the PCB ground plane.  
					Output Termination  
					The PCI-Express differential clock outputs of the  
					IDT5V41066 are open source drivers and require an  
					external series resistor and a resistor to ground. These  
					resistor values and their allowable locations are shown in  
					detail in the PCI-Express Layout Guidelines section.  
					PCB Layout Recommendations  
					For optimum device performance and lowest output phase  
					noise, the following guidelines should be observed.  
					Each 0.01µF decoupling capacitor should be mounted on  
					the component side of the board as close to the VDD pin as  
					possible. No vias should be used between decoupling  
					capacitor and VDD pin. The PCB trace to VDD pin should  
					be kept as short as possible, as should the PCB trace to the  
					ground via. Distance of the ferrite bead and bulk decoupling  
					from the device is less critical.  
					The IDT5V41066 can also be configured for LVDS  
					compatible voltage levels. See the LVDS Compatible  
					Layout Guidelines section.  
					2) An optimum layout is one with all components on the  
					same side of the board, minimizing vias through other signal  
					layers (the ferrite bead and bulk decoupling capacitor can be  
					mounted on the back). Other signal traces should be routed  
					away from the IDT5V41066.  
					This includes signal traces just underneath the device, or on  
					layers adjacent to the ground plane layer used by the device.  
					External Components  
					A minimum number of external components are required for  
					proper operation. Decoupling capacitors of 0.01 μF should  
					be connected between VDD and GND pairs (1,9 and 15,16)  
					as close to the device as possible.  
					On chip capacitors- Crystal capacitors should be  
					connected from pins X1 to ground and X2 to ground to  
					optimize the initial accuracy. The value (in pf) of these  
					crystal caps equal (C -12)*2 in this equation, C =crystal  
					L
					L
					load capacitance in pf. For example, for a crystal with a 16  
					pF load cap, each external crystal cap would be 8 pF.  
					[(16-12)x2]=8.  
					Current Reference Source Rr (Iref)  
					If board target trace impedance (Z) is 50Ω, then Rr = 475Ω  
					(1%), providing IREF of 2.32 mA, output current (I ) is  
					OH  
					equal to 6*IREF.  
					IDT® 4 OUTPUT PCIE GEN1/2 SYNTHESIZER  
					4
					IDT5V41066 REV D 112211