LPC55xx: IOCON setting, OD with on-chip pull-up resistor

[AmberLin]

Hi community,

Is it legal to config type D pin as open drain with pull-up mode?

Is there any adverse impact?

Best Regards.

Amber Lin.

[xiangjun_rong · Accepted solution]

Hi,

I suppose that the on-chip pull-up resistor is very large,the typical value is about 50K ohm, so the driving capability is small.

So external pull-up resistor with several K ohm for the open-drain pins is recommended.

Hope it can help you

BR

XiangJun Rong