Hello all,
I have a critical fail when I try to run the DAC38RF80EVM configuration in DUAL DAC mode, following the CMODE 3 example given in the DAC38RF8xEVM User's Guide.
Configuration :
-DAC38RF80EVM (5V / 1.5A) + TSW14J56 (5V / 3A),
-PC running Win 7, language set up in US English,
-Rohde & Schwarz SMA100A generates CW signal at 384 MHz (see Clock_384M.png), connected to J4 SMA connector on DAC38RF80EVM,
-DAC A and DAC B outputs from DAC38RF80EVM are connected to a SMA splitter, which goes to an R&S FSWP in Spectrum Analysis mode,
-All the hardware and software configuration are exactly those from the User's Guide instructions for CMODE3 (On-Chip PLL Clock Mode).
All is OK from beginning to step 11 included (in CMODE3, page 12 of the User's Guide PDF), see in the chronological order :
-GUI_QuickStart.png (GUI set up),
-HSDC.png (HSDC set up),
-HSDC_send_message.png (message that appears after clicking on "send", but seems normal according to some discussion here on TI-support),
-DAC_A.png (DAC A set up in GUI),
-Single_DAC.png (output seen on the FSWP, tone @ 2140.1 MHz as expected).
At this point all is OK, "PLL out of lock" indicators (in GUI / Clocking) are OFF, and power usage is 1.79A for the TSW, and 1.46A for the DAC EVM.
Problems start appearing when testing the Dual DAC mode, as shown in step 12 of the instructions :
-DAC B is set up according to the insructions (see DAC_B.png),
-When clicking on "UPDATE NCO", the second tone @ 1960.1 MHz appears (see Dual_DAC.png), but after a few seconds there's no output anymore, and the power usages fall to 1.46A and 0.82A respectively,
-Starting from here, it's impossible to get the board working as expected, and the the two indicators for the PLLs are ON (which means the PLLs are out of lock, see PLL_out_of_lock.png),
-The only way to make it work again is to restart the whole process.
This problem gets me quite confused actually, as I followed precisely the instructions from the User's Guide. It's also weird that it works in single DAC mode, and not in Dual DAC mode (it would have been less surprising if there was no output at all in any configuration). Please note that I have the same result even when changing the configuration and ticking/unticking the various checkboxes available in the DAC EVM GUI (e.g. : "Add path AB sample (adjacent DAC)" in "Digital(DAC A)", which we are not asked to tick, but appears ticked in the Figure 11 of page 12 of the User's Guide).
I hope I've given sufficient information on my environment and configuration, and thank you in advance for your help.
Regards,
Hugo
