DRA821U: Inquery about DDR pin package inside length

Jack

Part Number: DRA821U

Tool/software:

Hi DRA821U champ !

A customer is designing the LPDDR4 layout of DRA821U.
The data they are requesting is the length of the LPDDR4 interface from the wafer inside the CPU to the BGA pin.

To summarize, we are requesting the length data of the LPDDR4 interface (Address, CK, CS, RST, etc.) inside the CPU.
Can you please check the length of the DDR I/F pins?

Thanks.

Best Regards,

Jack

11 months ago

+1 Robert Eschler 11 months ago

TI__Guru 52695 points

Attached.

4062.DR821U_Pkg_DDR_Net_Delay_051421.xlsx

0 Lee Donggeun 10 months ago

Prodigy 41 points

Hi robert eschler

Thank you for your reply.
In the attached excel table, are the units stated in mm or inch?

0 Robert Eschler 10 months ago in reply to Lee Donggeun

TI__Guru 52695 points

Row 1 is header stating the units. The delay is in ps (pico-seconds)

0 Lee Donggeun 10 months ago

Prodigy 41 points

Is it possible to convert the unit ps (time) to the unit mm (length)? If possible, please tell me how to convert it.

+1 Robert Eschler 10 months ago in reply to Lee Donggeun

TI__Guru 52695 points

It is recommended to use time (not length) for skew control (most accurate). I believe all the values in the Jacinto7 LPDDR4 guideline are in time as well. Recommendation is to convert your PCB lengths and via into time.

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DRA821U: Inquery about DDR pin package inside length