AWR2944: AM2944: Delay time of MDC high to MDIO valid

Manikandan Murugan

Part Number: AWR2944
Other Parts Discussed in Thread: TDA4VM

Hi,

I need clarification about Delay time (MDC Low to MDIO valid) in AWR2944.

From the datasheet, Table 7-8, show the Max delay time is 190ns, but in Figure 7-20 it seems by 300ns. Pls confirm the delay parameters.

Thanks,

Mani M

over 1 year ago

0 E. Shareef over 1 year ago

TI__Genius 16640 points

Hello,

Thank you for reaching out to Texas Instruments.

A team member will respond to your query by Monday.

Best,

E. Shareef

0 E. Shareef over 1 year ago in reply to E. Shareef

TI__Genius 16640 points

Hello Mani,

Could you please elaborate here how you are coming to the conclusion that the max delay time in the figure is 300ns?

Thanks,

E. Shareef

0 Manikandan Murugan over 1 year ago in reply to E. Shareef

Prodigy 160 points

Hello Shareef,

If you look on the timing diagram, the delay approximately shows @300ns.

Thanks,

Mani M

0 E. Shareef over 1 year ago in reply to Manikandan Murugan

TI__Genius 16640 points

Hello,

P here is not defined properly and needs to be stated out. It would be the sum of high and low times, i.e. max of 320ns so the delay should come out to 150ns. I am attaching here a picture of the TDA4VM datasheet which uses the same IP: This is now schedueld to be updated in the future revision.

Hope this helps,

E. Shareef

0 Matt Carrell over 1 year ago

Prodigy 40 points

Hi Shareef,

If you assume a 150ns delay on a minimum 160ns length signal, then that provides no margin to the +/-10ns requirement at the phy input.

Does this design not have more margin than that?

Yes, this is a worst case requirement, but we still need to make sure we meet it while including other factors also.

Sensors

Sensors forum

AWR2944: AM2944: Delay time of MDC high to MDIO valid