TDA4VM: [TDA4x ] EVM board design conflict with schematic checklist.

Tao Han

Part Number: TDA4VM

Hi Experts:

At TDA4x schematic checklist request LPDDR4 reset signal add pull down resistor to ensure reset hold low during POR state.

But reference design E7 version add pull up resistor at LPDDR4 reset pin. (U11 pin T11)

It is conflict with schematic checklist. Could you please help us double check whether EVM design need optimize for LPDDR4 reset signal?

DNI R232 and place resistor at R228.

Best Regards!

Han Tao

over 5 years ago

0 Stanislav Stilyanov over 5 years ago

TI__Genius 15120 points

Hi Han Tao,

The schematic checklist recommendation is beneficial in the common case.

However, if you plan to use a low power mode with main domain OFF, and DDR in self-refresh, then DDR reset must be pulled high, or other mechanism implemented to drive it high. Otherwise DDR will be in reset and will not be able to enter and maintain self-refresh so contents will be lost.

Regards,

Stan

0 Tao Han over 5 years ago in reply to Stanislav Stilyanov

TI__Expert 6145 points

Hi Stan:

Thanks for your feedback. It is clear now.

Best Regards!

han tao

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TDA4VM: [TDA4x ] EVM board design conflict with schematic checklist.