DS90UH941AS-Q1: DS90UH941ASRTDRQ1 Reference clock confusion

HARI T O1

Expert 1285 points

Part Number: DS90UH941AS-Q1

Dear Team,

I am using DS90UH941ASRTDRQ1 in my design.

My VDDIO is 1.8V.

In the reference design the clock is coming from an oscillator which is working at 3.3V.

I won't be able to use that oscillator in my design .

Can you please suggest an alternate P/N for the oscillator.

The above image is taken from this document.

Regards

HARI

7 months ago

0 Ikram Haque 7 months ago

TI__Genius 11485 points

Hi HARI,

In your system are you using External REFCLK Mode or DSI Reference Clock Mode? The external clock to REFCLK0 is only needed for External REFCLK mode and the frequency should match the video pixel clock you are using.

This E2E FAQ has some information about this: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1050269/faq-ds90ub941as-q1-dsi-or-refclk-jitter-measurement

For a specific part, we can only recommend that the oscillator/crystal should meet the "Recommended Timing for External Clock Reference" section of the datasheet.

Best regards,
Ikram

0 HARI T O1 7 months ago in reply to Ikram Haque

Expert 1285 points

Hi Ikram,

May I Know how to use DSI Reference Clock Mode.

I am in the assumption that this IC work only with External clock.

Regards

HARI

0 Ikram Haque 7 months ago in reply to HARI T O1

TI__Genius 11485 points

Hi HARI,

It's covered in the "8.4.2.1 DSI Clock Modes" section of the datasheet, and relates to setting the BRIDGE_CTL Register (Address = 0x4F), BRIDGE_CFG2 Register (Address = 0x56) and the MODE_SEL configuration.

Best regards,
Ikram

0 HARI T O1 7 months ago in reply to Ikram Haque

Expert 1285 points

Hi Ikram,

Thank you.

One more question,just for curiosity ,if want to use external reference clk then VDDIO must be 3.3V.Please correct me if I am wrong.

Regards

HARI

0 Ikram Haque 7 months ago in reply to HARI T O1

TI__Genius 11485 points

Hi HARI,

VDDIO can be either 1.8 or 3.3 V depending on which option you choose for your system.

And the external reference clock (REFCLK) needs to meet:
- "1.8 V LVCMOS I/O" or "3.3 V LVCMOS I/O" voltage and current levels
- "Recommended Timing for External Clock Reference" for timing requirements

Best regards,
Ikram

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DS90UH941AS-Q1: DS90UH941ASRTDRQ1 Reference clock confusion