Application Note 101
PLL Evaluation Board
This application note details the basic connection, operation and software settings for the
Sirenza Phase Locked Loop (PLL) Evaluation Boards. The PLL EVB is designed to provide
an easy method of evaluating the Sirenza PLL products. The Sirenza PLL module consists of
a custom designed VCO, a commercially available PLL IC, a loop filter, and in some cases a
buffer amplifier to isolate the PLL from phase errors due to load variations.
Parts Needed for Proper Evaluation Board Operation:
• Sirenza PLL Evaluation PCB with part mounted on the EVB
• 25 Pin extension cable for parallel port (Note this is not a printer cable)
• Specification for PLL being used including Application Note.
• PLL controller Software (either from CD or downloaded)
• Power Supply
• Spectrum Analyzer (Agilent 8563E is recommended)
• BNC Cable
• SMA Cable
Downloading Software:
Download our PLL software from the following link:
Click on the link to download the PLL Controller 4.0 software (zip file)
Save the file to your computer and open, it using WinZip (or other zip file extraction program).
Double click Setup.exe and follow the installation instructions on screen
Use PLLCON-0308-0000000030 for the Serial Number
Connection Diagram:
10 MHz Reference
BNC Cable to back
of analyzer
Power Supply
Agilent 6626
Vcc2 (PLL VCC): +3 or +5
Volts usually
Vcc1 (VCC VCO): +5
Volts usually
Spectrum Analyzer
Agilent 8563E
RF Out
25 Pin Printer
Extension Cable
Running the Software:
1 Run the PLL Controller software from the Programs folder on the Start menu.
2 The first time you run the software, it will provide a list of the parallel ports that
are available on your computer. Choose the port that you will use to control the
PLL synthesizer.
3 Select "Open App Note..." from the File menu of the PLL Controller. From the
AppNotes folder, select the appropriate app note. For example, with the PLL3502140, choose appnote113-.van. The correct application note can be determined
from the product specification.
4 Many of the PLL modules use a PLL IC with variable charge pump current. The
loop of each module is optimized for a charge pump setting. This is specified in
the specification sheet. For example, with the PLL400-1143, make sure the
Option number is set to 100. This is the default option when loading the 109 app
5 Make sure the Reference Input used is 10 MHz.
6 Enter the channel spacing in kHz. The PLL module is optimized for a particular
step size. This is available from the specification sheet under step size.
7 Enter the Desired Output Frequency.
8 Press the Send All button.
Each time the Output Frequency is changed, pressing the Send All button will reprogram
the PLL synthesizer.
Common Troubleshooting Issues:
No or low RF Output: check to determine there is current being supplied to the
unit, this is usually a result of no DC applied to the unit.
Excess Loop Peaking (above 4 dB): This is normally caused by an incorrect
command word being sent to the PLL. Usually this is either the control
word setting the wrong phase detector current or the R-word with an
incorrect step size set.
The loop is not locked: Check to see there is a reference signal being applied and
the amplitude is between 2 and 4 Volts peak-to-peak (for +5 V operation
of PLL IC). The other common issue is not all words have been sent to the
PLL module. Make sure all words have been sent by pushing the SEND
ALL button..
Excess Noise on the signal: This is normally the result of an incorrect control
word setting. Check the Option specified on the specification.
Programming and troubleshooting aids:
The PLL controller software has programming aids and trouble shooting aids built in.
The bit patterns for all words are displayed for any combination of output frequency and
reference used for the unit. Use of this in conjunction with either an oscilloscope or word
analyzer is useful in troubleshooting integration issues.