Texas Instruments CDCE62002EVM - CDCE62002 Evaluation Module CDCE62002EVM CDCE62002EVM 데이터 시트
제품 코드
CDCE62002EVM
7
Configuring the Board
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Configuring the Board
Step 8: PLL Dividers Selection
The input, feedback and prescaler dividers can be selected by clicking on each tab in the GUI which
opens up a popup window displaying all the possible selections of those dividers. Care must be taken in
choosing these dividers, along with the VCO, charge pump and loop filter, such that the on-chip PLL of the
CDCE62002 can operate in a stable closed loop manner. Refer to the CDCE62002 data sheet for further
information on appropriate configuration of the PLL for closed loop operation. After the dividers are set
accordingly, the PLL LOCK indicator display on the GUI would be lit up in bright green color. Also the
on-board LED D33 would be lit to indicate PLL lock. The output dividers for each output can also be
chosen from possible selections displayed in the popup window which open up by clicking the output
divider tab in the GUI. Each output divider can also be disabled.
The input, feedback and prescaler dividers can be selected by clicking on each tab in the GUI which
opens up a popup window displaying all the possible selections of those dividers. Care must be taken in
choosing these dividers, along with the VCO, charge pump and loop filter, such that the on-chip PLL of the
CDCE62002 can operate in a stable closed loop manner. Refer to the CDCE62002 data sheet for further
information on appropriate configuration of the PLL for closed loop operation. After the dividers are set
accordingly, the PLL LOCK indicator display on the GUI would be lit up in bright green color. Also the
on-board LED D33 would be lit to indicate PLL lock. The output dividers for each output can also be
chosen from possible selections displayed in the popup window which open up by clicking the output
divider tab in the GUI. Each output divider can also be disabled.
Step 9: Write to CDCE62002 EEPROM
To write any particular setting to the EEPROM (locked or unlocked), the menu item at the top of the GUI
titled “Tool” must be clicked which would highlight the items “Write EEPROM Unlocked” and “Write
EEPROM Locked” as part of a drop-down menu. Choosing the appropriate one after setting the desired
PLL configurations would result in writing to the EEPROM in its appropriate mode.
To write any particular setting to the EEPROM (locked or unlocked), the menu item at the top of the GUI
titled “Tool” must be clicked which would highlight the items “Write EEPROM Unlocked” and “Write
EEPROM Locked” as part of a drop-down menu. Choosing the appropriate one after setting the desired
PLL configurations would result in writing to the EEPROM in its appropriate mode.
Figure 7. Tools – Write to EEPROM
The CDCE62002EVM can be powered from the USB power supply or from an external source. The
CDCE62002EVM only needs a USB cable attached for programming purposes however for test
measurements it is recommended to also use an external 3.3V power supply. Test measurements can
also be taken with only the USB supplied power however due to USB power variances results may
degrade. It is also possible to program the CDCE62002 and then disconnect the USB cable with minor
board configuration changes.
CDCE62002EVM only needs a USB cable attached for programming purposes however for test
measurements it is recommended to also use an external 3.3V power supply. Test measurements can
also be taken with only the USB supplied power however due to USB power variances results may
degrade. It is also possible to program the CDCE62002 and then disconnect the USB cable with minor
board configuration changes.
Configuration for Programming and Testing (with USB cable attached) (Default Configuration)
The CDCE62002EVM is configured by default to operate with the USB cable attached and a 3.3V power
supply added to EXT VDD and GND. In this configuration the USB microcontroller is powered by the USB
port’s 5V supply while the CDCE62002 is powered by the 3.3V external supply. This setup is optimal for
programming the CDCE62002 while also taking measurements. This configuration removes the power
variation found in USB power supplies by isolating the CDCE62002 from the USB supply.
The CDCE62002EVM is configured by default to operate with the USB cable attached and a 3.3V power
supply added to EXT VDD and GND. In this configuration the USB microcontroller is powered by the USB
port’s 5V supply while the CDCE62002 is powered by the 3.3V external supply. This setup is optimal for
programming the CDCE62002 while also taking measurements. This configuration removes the power
variation found in USB power supplies by isolating the CDCE62002 from the USB supply.
Configuration for Programming (using USB power)
The CDCE62002EVM can use power supplied through the USB cable as its sole power source. However
due to power supply variances in the USB supply this configuration is not recommended for
measurements. This setup is for saving configuration settings to the CDCE62002 and later powering the
device from its internal memory (useful during performance testing of the device). In this configuration
JP_3_3 must be moved from its default position to the new position shown below. Also the “Enable EVM
Power” box must be checked on the EVM GUI interface software.
The CDCE62002EVM can use power supplied through the USB cable as its sole power source. However
due to power supply variances in the USB supply this configuration is not recommended for
measurements. This setup is for saving configuration settings to the CDCE62002 and later powering the
device from its internal memory (useful during performance testing of the device). In this configuration
JP_3_3 must be moved from its default position to the new position shown below. Also the “Enable EVM
Power” box must be checked on the EVM GUI interface software.
SCAU034 – June 2009
Two/Four Output Low Phase Noise Clock Evaluation Board
7