DAC38RF83: SYSREF+/-, DACCLK+/-

Shlomi Is'hakov

Intellectual 270 points

Part Number: DAC38RF83
Other Parts Discussed in Thread: LMK04616, , LMK04828

I want to connect the LMK04616 to SYSREF+/-, DACCLK+/- inputs.

The LMK04616 outputs are 8mA HDSD, 4mA HDSD and 16mA HCSL.

Which of the option I need to use and what kind coupling (AC\DC) is needed?

What is the termination I need?

Kind regards,

Shlomi

over 5 years ago

0 Ebenezer Dwobeng over 5 years ago

TI__Genius 9695 points

Hi Shlomi,

DC coupling is recommended but the SYSREF is biased internally at 500mV and requires 400mVpp swing. I will recommend you check with the LMK04616 team if it is possible to configure the clock device common mode and swing to be compatible with the DAC38RF83. If they are not compatible, then the only option you have is to AC couple.

Thanks,

Eben.

0 Shlomi Is'hakov over 5 years ago in reply to Ebenezer Dwobeng

Intellectual 270 points

I want to AC couple.

How it's done?

I want to use HDSD 8mA. Is that problem?

Does it apply also for DACCLK?

Kind regards,

Shlomi

0 Ebenezer Dwobeng over 5 years ago in reply to Shlomi Is'hakov

TI__Genius 9695 points

Hi Shlomi,

To AC couple, use capacitors (0.1uF) to provide DC isolation between the LMK common mode and the DAC common mode.

Make sure to terminate the LMK appropriately for HSDS 8mA. You can refer to LMK04828 datasheet for how to terminate HSDS 8mA

Thanks,

Eben.

0 Shlomi Is'hakov over 5 years ago in reply to Ebenezer Dwobeng

Intellectual 270 points

Hi Eben,

I looked at the LMK4828 datasheet and I didn't find how to terminate HSDS.

Can you write me on what page to look?

Thank,

Shlomi

0 Ebenezer Dwobeng over 5 years ago in reply to Shlomi Is'hakov

TI__Genius 9695 points

Hi Shlomi,

Send me a private message with your email and I will forward you a document on this.

Thanks,

Eben.

0 Shlomi Is'hakov over 5 years ago in reply to Ebenezer Dwobeng

Intellectual 270 points

i sent

0 Ebenezer Dwobeng over 5 years ago in reply to Shlomi Is'hakov

TI__Genius 9695 points

I also sent the presentation to you so I will close this thread.

Data converters

Data converters forum

DAC38RF83: SYSREF+/-, DACCLK+/-