LP2998-Q1: minimum VDDQ rating for DDR3L

Ross Parlour

Part Number: LP2998-Q1
Other Parts Discussed in Thread: TPS51200, TPS51200-Q1

Hi Qian,

Thank you for your prompt response to this. I have just one final question regarding the VDDQ voltage. What is the minimum VDDQ rating for DDR3L application? Since a tolerance of 1.283V won’t work for my customer, if they take into account the voltage drop.

Regards,
Ross

over 5 years ago

0 Qian Chen over 5 years ago

TI__Mastermind 24075 points

HI Ross,

In JEDEC spec, the minimum VDDQ voltage for DDR3L is 1.283V.
Are you saying the VDDQ voltage could be even lower in customer's application?

Thanks
Qian

0 Ross Parlour over 5 years ago in reply to Qian Chen

TI__Intellectual 1240 points

Hi Qian,

They need to cover losses coming from the traces, and the voltage drop on the wires. So they need to insure the regulator will be operational even with a VDDQ in the ranges of 1.2V.

With this in mind, they are now evaluating the TPS51200, as it has a better VDDQ.

Тhis has been very helpful. Thank you.

Ross

0 Qian Chen over 5 years ago in reply to Ross Parlour

TI__Mastermind 24075 points

Hi Ross,

I would suggest to consider TPS51200-Q1 if VDDQ voltage goes to 1.2V.
Keep in mind, if VDDQ goes to 1.2V, VTT will be 0.6V and VTT voltage may be out of DDR3L spec.

Thanks
Qian

Power management

Power management forum

LP2998-Q1: minimum VDDQ rating for DDR3L