https://community.nxp.com/t5/LPC-Microcontrollers/LPC55xx-IOCON-setting-OD-with-on-chip-pull-up-resistor/m-p/1753236#M54650 <P>Hi,</P> <P>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.</P> <P>So external pull-up resistor with several K ohm for the open-drain pins is recommended.</P> <P>Hope it can help you</P> <P>BR</P> <P>XiangJun Rong</P> <P>&nbsp;</P> Tue, 07 Nov 2023 05:23:52 GMT xiangjun_rong 2023-11-07T05:23:52Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC55xx-IOCON-setting-OD-with-on-chip-pull-up-resistor/m-p/1753153#M54648 <P>Hi community,</P><P>Is it legal to config type D pin as open drain with pull-up mode?</P><P>Is there any adverse impact?</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="AmberLin_0-1699324385441.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/248713iA8156795A9F2BC55/image-size/medium?v=v2&amp;px=400" role="button" title="AmberLin_0-1699324385441.png" alt="AmberLin_0-1699324385441.png" /></span></P><P>Best Regards.</P><P>Amber Lin.</P> Tue, 07 Nov 2023 02:38:42 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC55xx-IOCON-setting-OD-with-on-chip-pull-up-resistor/m-p/1753153#M54648 AmberLin 2023-11-07T02:38:42Z https://community.nxp.com/t5/LPC-Microcontrollers/LPC55xx-IOCON-setting-OD-with-on-chip-pull-up-resistor/m-p/1753236#M54650 <P>Hi,</P> <P>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.</P> <P>So external pull-up resistor with several K ohm for the open-drain pins is recommended.</P> <P>Hope it can help you</P> <P>BR</P> <P>XiangJun Rong</P> <P>&nbsp;</P> Tue, 07 Nov 2023 05:23:52 GMT https://community.nxp.com/t5/LPC-Microcontrollers/LPC55xx-IOCON-setting-OD-with-on-chip-pull-up-resistor/m-p/1753236#M54650 xiangjun_rong 2023-11-07T05:23:52Z