TPS650861: VREF for DDR4

Dice-K

Part Number: TPS650861
Other Parts Discussed in Thread: TPS51200

Hi support team,

I understand that the TPS650861 does not have a VREF power supply for DDR4.
A method of dividing VDDQ to generate VREF is introduced.
Is it safer to add a dedicated IC such as TPS51200 after TPS650861?

Regards,
Dice-K

over 5 years ago

0 Layne J over 5 years ago

TI__Genius 12735 points

Hi Dice-K,

The VTT LDO was designed specifically to provide the termination voltage for a given DDR module. I have not seen any risk or issues caused by using the VTT LDO to provide the VDDQ/2 voltage. Is there a specific concern you have?

Best regards,

Layne J

0 Dice-K over 5 years ago in reply to Layne J

Mastermind 7470 points

Hi Layne,

I think VTT LDO is for VTT and not for VREF.

So I'm looking for a best way to generate VREF.

Best regards,
Dice-K

0 Dice-K over 5 years ago in reply to Dice-K

Mastermind 7470 points

Hi Layne,

Is there a better way than using the TPS51200?

Best regards,
Dice-K

0 Layne J over 5 years ago in reply to Dice-K

TI__Genius 12735 points

Hi Dice-K,

I am not sure about using TPS51200 to supply the VREF voltage, this is a device from a different team within TI. In the past we have seen customers use a resistor divider on the BUCK6 output to supply VREF. If you would rather use a separate component to provide VREF I would be happy to send your question to the expert on those devices (like TPS51200) who can provide more input than I can.

Best regards,

Layne J

0 Dice-K over 5 years ago in reply to Layne J

Mastermind 7470 points

Hi Layne,

I have confirmed it in the thread of TPS51200.
e2e.ti.com/.../927486

Thank you for your support.

Best regards,
Dice-K

0 Layne J over 5 years ago in reply to Dice-K

TI__Genius 12735 points

Hi Dice-K,

Glad to hear you found a resolution. I will close this thread now.

Best regards,

Layne J

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TPS650861: VREF for DDR4