Adau1701 behaving abnormally

Hello Alxve,

What I first really wanted to see is the SigmaStudio schematic and it may still be a good idea however, I did look at the hardware schematic you provided and I did see this error.

You are connecting the crystal to the PLL Loop filter pin! This will cause all sorts of issues with the PLL. The loop filter needs to stand alone.

Remove this connection:

You can see this in the datasheet application schematic:

Once this is fixed let's see where you stand. There may be some other issues.

Dave T

Hello Dave, thank you for your reply.

I have removed that connection also I noticed something I didnt use a 100 ohm damping resistor.

Does that make it unstable?

Also my mclki to gnd resistance reads .141 ohms, is my dsp chip healthy or not?

I did remove that pll loop but I had the same unwanted noise on dac.

But, when i link compile connect and link compile downloaded several times it worked.

Super inconsistent though, according to datasheet i connected PLL LF to 3.3v and not 1.8v DVDD

And for sigma studio blocks, i had a simple sine wave tone and a gain block and a volume and finally the output sometimes it works but sometimes it doesnt.

Hello Alxve,

Thanks for pointing out some other things for me to look at more closely. There are some huge problems here.

First, you are not using the internal DVDD regulator that would reduce the 3.3V down to 1.8V

However, to make things worse, You have the two DVDD input pins tied together and tied to nothing!! No voltage at all. I pointed to these with the two arrows.

Also, you have a 10uf caps but it also needs to have two 100nf caps placed close to the pins to decouple noise from getting into DVDD.

Here is what is missing. this is a screenshot from the datasheet.

The MCLKIN ground resistance does not look good.

I need to run so this is another quick response.

Dave T

Oh yes dave I did use a 1.8v supply to feed the dvdd area.
it was seperate since I forgot to add a transistor in my pcb.

I am never used this dsp before so just learning right now so that I can use Analoge's more advanced and powerful dsps.

By the way, do I need a damping resistor with the crystal a 100 ohms one if I dont use one what could possibly happen with the dsp?

Hello Alxve,

OK, so that is good that there was a voltage there. Timing becomes another question. You mentioned the EEPROM so I assume you re selfbooting?

Regarding the resistor. This is mostly for signal integrity reasons to limit the spikes and overshoot. However, it might also limit any surge currents to the crystal. I would have to read the crystal datasheet. Ao I am not exactly certain what could happen without it. However, we certainly put this resistor on all the time.

Dave T

Hello Dave!
Nope, I kept selfboot pin to low. Reset pin was high during bootup.
And I am using an esp32 IE N16R8 I dont know if that would cause timing issues. Since I keep pressing link compile download several times before it successfully makes that sine tone odd enough.
The crystal I am using is ABLS-12.288MHZ-B2-T.
.
I wanted to ask, what is the reason that I had timing issues so bad? I dont think I did anything wrong with my schematics.