How to connect the Not Connected Pin in LX2160?

[deega_jung]

Dear NXP Support team,

I have a question between LX2160 data sheet and reference schematic.

In the LX2160 data sheet, "Not Connection" is guided to be left floating, but on page 18 of the reference circuit "LX2160-RDB-SCH", some pins are connected to the power rail with VDD.

For inquiries, when designing a circuit, how should I connect the NC_P28/R27/U27/V28/W27/AA27/AC27/AD28/AE27/AF28/AG28 pins among the NC (Not Connection) pins? Connect to VDD or Left Floating?

Refer to the below capture is from the reference schematic "LX2160-RDB-SCH",

Thanks,

Deega Jung

[yipingwang]

The LX2160ARDB was designed to support both LS2081A and LX2160A SOC's. The mentioned NC pins connected to VDD on RDB are required for LS2081A operation. For LX2160A, follow the guidelines given in LX2160A datasheet that is, NC pins should be left floating.

[deega_jung]

Hi uipingwang,

Thank you for your reply.

I didn't know because I couldn't see the information about the LS2081A SOC.

As a result of my review, the NC pins of NC_P28/R27/U27/V28/W27/AA27/AC27/AD28/AE27/AF28/AG28 are located in the area marked with a red-box in Layer-10 on the reference EV-kit PCB.
It appears to have been connected to the bypass CAP (C434) of the VDD power rail of Layer-10 and to have connected the NC pins to the VDD to secure the current path. What is your opinion?

Also, is there a way to check the datasheet of LS2081A? If you can, I would appreciate it if you could share.

Thanks,

Deega

[yipingwang · Accepted solution]

For LX2160A based design, successful operation is guaranteed when "NC pins" should be left floating. It should not be connected to VDD. Strictly follow the guidlines as mentioned in LX2 datasheet.

[deega_jung]

Dear yipingwang,

Thank you for your comment. 

Thanks,

Deega

[yipingwang]

Confirming with the AE team.