Datasheet

6.2 Manual PLL Block Selection (Advanced Control)
www.ti.com Chronos GUI Software
This GUI helps users to set the PLL without having to manually alter all the blocks individually within the
PLL. If a user is familiar with the general operation of PLLs, one may activate individual control of the PLL
blocks by clicking on the Advanced Control button. A new window appears, as shown in Figure 7 .
Figure 7. CDCE421A Advanced Controls Pop-Up Dialog
Table 1 summarizes the various menu options available in this dialog window.
Table 1. Advanced Control: Software Setting Options
Section Function
Selects between VCO1 and VCO2. Only one VCO can be
VCO Select used during operation. See the CDCE421A product data
sheet for VCO tuning ranges.
The prescalar selection will be determined in conjunction with
Prescalar the VCO and output divider selection. See the CDCE421A
product data sheet to determine the proper setting.
The output divider will be determined in conjunction with the
Output Divider. VCO and prescalar settings. See the CDCE421A product
data sheet to determine the proper setting.
Driver Select Selects between LVPECL or LVDS.
This option should be activated with using LVPECL output.
PECL config When selected, the USB controller will enable onboard
LVPECL termination.
Selects appropriate charge pump current. See screen
Charge Pump Current.
shotsxx for recommended configurations.
Bias 0 should be used at all times. Bias 1 is a reserved test
Loop Filter Bias Select
mode for TI.
SCAU031 – June 2009 10.9-MHz to 1.175-GHz, Low Phase Noise Clock Evaluation Board 9
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