ADAU145x-No CLKOUT.

You must turn on MCLK_OUT, set Base x FS Coefficient (ADAU145x Register Control -> Clock_Control) and enable power High Precision CLK (ADAU145x Register Control -> Power_Clocking).

Thanks, it's not that though.

In further fiddling I've found PLLFILT pin is sat at 3.3v rather than the 1.65v to 2.1v it should be, according to the datasheet. Though I can't see why.

Have replaced the IC again with exactly the same results, 3.3v on PLLFILT. Have checked for shorts and opens with multimeter, all appears to be ok. Has anyone else had the same issue?

May have found a bug in sigmastudio 3.11. With USBi connected to laptop but not to ADAU1450, link-compile-download always results in 'active:downloaded', which is clearly not correct. Performing same test with ADAU1701 brings up the expected error pop up. This, I think, at least explains why changing registers made no difference on my PCB!

Hello Alex,

You say you are not getting the expected output? What output are you getting and what are you expecting?

Attach your project and then attach the ADAU145x section of the schematic and any other relevant clocking section.

Thanks,

Dave T

Hi Dave, thanks,

On CLKOUT pin there is a very distorted representation of the clock, around 50mV. I get this with the clock buffer installed or not. Would expect to see around 3V amplitude clock, nice and clean.

Attached relevant part of schematic. Project is just input straight to output so have not attached it. Following on from post 4- I can't successfully program the device yet, so not relevant at the moment, I don't think.

I *think*, priority is finding out why PLLFILT has 3.3v on it, need help with things to look for.

Thank you,

Alex.

Hello Alex,

Could the part be held in reset? Is the reset pin shorted to the ground pin next to it?

What is connected to the reset pin? It needs to be pulled up to IOVDD through a weak pull-up. I would also filter it if nothing is tied to it.

What do you have for the DVDD voltage out of the regulator?

Thanks,

Dave T

Hi Dave,

Reset circuit can be seen here (attached) It's essentially the same as on the eval board.

Reset function seems to be working correctly, holding reset line at 3.3v. Have tried manually keeping the device in reset (grounded) to ensure all start up functions have definitely finished, before bringing it out of reset. Not that.

DVDD measures 1.2V.

Alex.

Hello Alex,

Do me a favor and don't upload your images to the server you are using that inserts advertisements. This is not appropriate for this forum. Insert them using the tools in the forum.

OK, so the device is probably not in reset...

There are no many things to look for it so it makes this tough to do remotely. Use your ohm meter and see if the clkout pin is shorted to a ground or other pin that is being held low? Try to lift the pin, or cut the trace close to the pin and see if it comes up.

You can send me your project and I can see if it comes up properly on the evaluation board. Then we can be certain it is not a setting in the project file.

If you do not make any further progress on this after these suggestions then I can setup a private conversation where you can send the entire schematic and layout and I can look a little deeper for an answer.

Thanks,

Dave T

Hi Alex,

I removed your external links due to external viewer banner advertising. Your second link has been recreated as an attachment.

Thank you,

Lisa

Hello,

Sorry, had issues in attaching file for post 5 (which still doesn't open for me), so used an external image host. (Never actually saw any adverts on there- adblocker!) Apologies.

Have checked again that there are no shorts either from CLKOUT, PLLFILT, or anywhere else, can't find anything.

Can send you the project file if you prefer, I have checked it on my eval board though and it works. Incidentally, clock signal is present on CLKOUT on the eval board without anything programmed to it.

Private conversation may be best, if that's ok.

Much appreciated.

Alex.

All sorted. Was down to a poor connection on my board to the USBi.

For anyone else reading with similar problem- At some point I must've written a program to the EEPROM on my eval board and forgotten I had done so, this made me think CLKOUT and serial line clocks should be present with no program loaded, this is absolutely not the case. After sorting my connection and programming the device, all clocks sprang into action.