AWR2243: awr2243 Cascade, 1 Master 5 Slaves, Master chirps, Slaves do not

Hi,

Based on the information provided it is difficult to understand what could cause this behavior.

Are you able to adapt the mmWave link cascade example to your custom board?

C:\ti\mmwave_dfp_02_01_05_03\ti\example\mmWaveLink_Cascade_Example

Thank you

Cesar

Yes, we are utilizing an adapted versioin of the example software. 

Hello Glen,

Are you configuring the master in SW triggered mode (in the Frame config API) and the slave devices in HW triggered mode? How is the digital SYNC IN connection made between the 6 devices? is the SYNC_OUT from the master taken and buffered to back to all the 6 devices? I am referring to the digital SYNC signal not the 20Ghz SYNC signal.

Regards,
Vivek 

Hello Vivek, 

Thank you for the response. Yes the Master is set to SW trigger and the slave devices are HW trigger. The Sync Out signal, SOP1 as well right? is taken through a digital clock mux and distributed to all the slave devices as well as the master device.

Vivek, i have since measured this signal on an oscilloscope, the master device is outputting a pulse ~15ns wide, and confirmed each slave is receiving the signal. The VIOIN is powered by a 1.8V power supply and this signal is getting just over 1.5V, enough to register a "high" signal to the chips. Correct and advise as needed. Thank you

yes, i am using a mux. the power level is 1.63V. according to the datasheet this should be enough to be a High signal?

Hello Vivek, 

please see these scope captures and advise. I mis-spoke before, we are using a buffer for this signal. and our pulse is ~25ns, see image.

Hello Glen,

Why is the signal reaching only 1.5V ? is the VIO supply not properly set to 1.8V? Can you share the schematics?

Regards,

Vivek

Vivek, the power going into VIOIN, is set to 1.8V and measures that exacltly going into the awr chip. thank you for your help so far

Hello Glen,

I was referring to the buffer supply. I assume the wave for m you shared above is of the SYNC IN signal, which is the output of the buffer. Is that correct? Are all the 6 outputs of the buffer looking similar? 

The schematic snapshot of the AWR section is unclear, can you share the pdf version of an image with more clarity? 

Regards,

Vivek

yes, the buffer is powered by the 1.8V supply, measures at 1.8V. all 6 signals look similar to the scope capture above. That scope capture is on the ouput of the buffer going to each slave device.awr2243.pdf

Hello Glen,

Could the below circuit on the SYNC IN lines be loading the signal? Can you remove this RC components and verify if you see proper 1.8V level on the SYNC IN pins?

Regards,
Vivek