Analog Devices EVAL-ADF4150EB1Z User Manual page 10

UG-380
Use the Frequency text box in the Reference section to set the
correct reference frequency. The default reference on the
software window is at 25 MHz and matches the frequency of the
TCXO present on the board.
Use the Output Frequency section to control the output
frequency. To achieve single-tone on the RF output, type the
desired output frequency in the Activate f1 text box (in mega-
hertz) and ensure that Stop is selected in the Dynamic section
under Output Frequency. Selecting the Alternate option
causes the frequency on the VCO output to switch between the
Activate f1 and Activate f2 values. The delay time between
frequency switches is controlled by the Approximate Delay
option. The third option of the Dynamic section, Sweep, allows
the output frequency to constantly change with the frequency
step set by Channel Spacing starting from Activate f1 until it
reaches Activate f2. When the Activate f2 frequency is reached,
the sweep is repeated. Note that the Sweep option is not allowed
if the Activate f1 and Activate f2 frequencies require different
settings for the output divider (the Out Div box in the Outputs
section). However, the Alternate option allows both frequencies
to be achieved with different output divider values.
Some register settings may need to be set manually. Click the
Register 1 to Register 5 buttons to open the register settings
windows (see Figure 18).
Click the REGISTERS button to display the binary and
hexadecimal values for all registers, as shown in Figure 20.
When a new register setting value is entered (see Figure 18),
the relevant Update Rx (where x = 0 to 5) button becomes red,
indicating that it must be clicked to program the part with the
new value. Clicking the Update ALL button programs all
register values simultaneously.
Click the OK button to confirm the new value in the Register x
Settings (where x = 1, 2, 3, 4, or 5) window (see Figure 18).
Click Update Rx to program the part with the new value. The
new value is retained in the Register x Settings window if it is
opened again.
If the value entered is outside of the range specified in the
ADF4150 data sheet, an error message appears and the field is
automatically updated to the lowest or highest value within the
allowed range. Some limits are changed dynamically based on
the values of other registers; for example, the highest allowed
value for Phase in Register 1 Settings window depends on
current value of the modulus (MOD in the Settings section),
which is calculated based on the data from the Reference
section and the Channel Spacing box in the Output Frequency
section.
Click the Cancel button to abandon a register value change, and
the new value is not retained in the Register x Settings window
if it is opened again.
By clicking the Frac/Mod button, you can choose different
modes of operation, including programming of specified
integer, modulus, fractional, and output divider values. The
output frequency and channel spacing are calculated automati-
cally when the values shown in Figure 19 are entered in the
Frac_Mod_Form window.
Rev. 0 | Page 10 of 24
Evaluation Board User Guide