GC5325SEK Initial Testing Help

Hello

If the GC5325 SEK came with the DSP weullfen adapter, or this is the one we modified when I was in India, then the FPGA firmware is OK.  If this unit has recently

been updated to add the DSP Weullfen adapter, then the FPGA firmware must be updated.  Contact Jim Seton for firmware (j-seton@ti.com)

On the board silkscreen SW5-4 needs to be positioned to have the DSP load the SPI commands.  Follow the board silkscreen for the switch setting.

Using the table on page 6 of the User Guide, the SW5 SW1,SW2 position will determine what the output frequency of the clock to the TSW3100.  This should be 122.88Mhz

if the VCXO is 737.28, the jumpers are set for the internal VCXO, and the SPI programming has worked.  the LOCK LED should be lit, if the CDC part is programmed, and the base clock is present.   Please check SMA J2 (this is the SMA output to the TSW3100).

There are also soldered jumpers on the GC5325 EVM that allow for an externa VCXO.  The other reason the clock may not work is that you need an external 6dbm clock input

The GC5325 also needs an external LO.  The range of operation, can also change jumper positions (se page 5) described in the user guide.

Once you have the clock LOCK LED, and the approrpriate clock output from the J2, and the LO injected, use a spectrum analyzer to check the output of the Tx (not in loopback mode).  You should see a -20 to -4dbm output from the Tx output.

In some cases to actually use the external loopback, you need to have the Minicircuit ZL3500 predriver in the Tx to Amp to Feedback path.

Regards,

Radio Joe