LP2981A: To know the concern of connect the LP2891 pin4 (NC) to 3.3V

kevin.huang_FJXM

Part Number: LP2981A

HI:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/998768/lp2981-to-know-the-concern-of-connect-the-lp2891-pin4-nc-to-ground/3694604

The LDO LP2981A-50DBVR of TI and pin 4 are NC. If the NC pin is always connected to 3.3V, what is the problem.

over 2 years ago

0 Juliette over 2 years ago

TI__Mastermind 18466 points

Hello Kevin,

I will check the bond diagram of this part to verify if the pin is internally connected. If it is not, there is no issue with this part being connected that way. We typically recommend connecting these pins to ground as a way to minimally improve thermal performance.

Best,

Juliette

0 kevin.huang_FJXM over 2 years ago in reply to Juliette

Expert 2925 points

HI Juliette:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/998768/lp2981-to-know-the-concern-of-connect-the-lp2891-pin4-nc-to-ground/3694604

pin 4 does have a bond wire connect to the die of the chip.

If the NC pin is always connected to 3.3V, what is the problem.

0 Juliette over 2 years ago in reply to kevin.huang_FJXM

TI__Mastermind 18466 points

Hey Kevin,

I verified that both the A and the non-A version have the same bond diagram and it seems that they do. Like in the previous E2E thread, connecting this pin will compromise the accuracy of this part.

Best,

Juliette

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LP2981A: To know the concern of connect the LP2891 pin4 (NC) to 3.3V