元器件交易网
PRELIMINARY
IntegratedCircuit
Systems, Inc.
CRYSTAL-TO-LVCMOS / LVTTL
FREQUENCY SYNTHESIZER WITH FANOUT BUFFER
recommended to have one decouple capacitor per power pin.Each decoupling capacitor should be located as close as pos-sible to the power pin. The low pass filter R7, C11 and C16 forclean analog supply should also be located as close to the VDDApin as possible.
ICS84025
SCHEMATIC EXAMPLE
Figure 4A shows a schematic example of using an ICS84025. Inthis example, the input is a 25MHz parallel resonant crystal withload capacitor CL=18pF. The frequency fine tuning capacitorsC1 and C2 is 22pF and 18pF respectively. This example alsoshows logic control input handling. The configuration is set atF_SEL[1:0]=11 therefore the output frequency is 125MHz. It is
FIGURE 4A. ICS84025 SCHEMATIC EXAMPLE
84025EM
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REV. A APRIL 16, 2003