https://community.nxp.com/t5/LPC-Microcontrollers/ADC-VREFN-in-LPC5514JBD64E/m-p/1314888#M45995 <P>Hello&nbsp;&nbsp;<SPAN>embedded_eng_</SPAN></P> <P><SPAN>After confirm with internal,&nbsp; VREFN is tied to VSSA internally.</SPAN></P> <P>&nbsp;</P> <P>&nbsp;</P> <P><SPAN>BR</SPAN></P> <P><SPAN>Alice</SPAN></P> Thu, 29 Jul 2021 01:01:43 GMT Alice_Yang 2021-07-29T01:01:43Z https://community.nxp.com/t5/LPC-Microcontrollers/ADC-VREFN-in-LPC5514JBD64E/m-p/1312841#M45954 <P>Hi,</P><P>I'm planning a PCB with the LPC5514JBD64E MCU.</P><P>The user manual&nbsp;specify that "VREFL is <STRONG>always</STRONG> from an external pin and must be at the same voltage potential as VSSA"&nbsp; (39.4.1)</P><P>UM11295,&nbsp;<A href="https://www.mouser.com/pdfDocs/UM11295.pdf" target="_blank">https://www.mouser.com/pdfDocs/UM11295.pdf</A></P><P>&nbsp;</P><P>&nbsp;</P><P>On the other hand, the datasheet&nbsp;specify that&nbsp;VREFN is not connected to an external pin(64 pin HTQFP) (Table 3. Pin description)</P><P><A href="https://www.nxp.com/docs/en/nxp/data-sheets/LPC55S1x_PDS.pdf" target="_blank">https://www.nxp.com/docs/en/nxp/data-sheets/LPC55S1x_PDS.pdf</A></P><P>&nbsp;</P><P>How can I use the ADC?</P><P>Does VREFN is internally connected to GND?</P><P>&nbsp;</P><P>&nbsp;</P><P>&nbsp;</P> Sun, 25 Jul 2021 08:09:36 GMT https://community.nxp.com/t5/LPC-Microcontrollers/ADC-VREFN-in-LPC5514JBD64E/m-p/1312841#M45954 embedded_eng_ 2021-07-25T08:09:36Z https://community.nxp.com/t5/LPC-Microcontrollers/ADC-VREFN-in-LPC5514JBD64E/m-p/1314888#M45995 <P>Hello&nbsp;&nbsp;<SPAN>embedded_eng_</SPAN></P> <P><SPAN>After confirm with internal,&nbsp; VREFN is tied to VSSA internally.</SPAN></P> <P>&nbsp;</P> <P>&nbsp;</P> <P><SPAN>BR</SPAN></P> <P><SPAN>Alice</SPAN></P> Thu, 29 Jul 2021 01:01:43 GMT https://community.nxp.com/t5/LPC-Microcontrollers/ADC-VREFN-in-LPC5514JBD64E/m-p/1314888#M45995 Alice_Yang 2021-07-29T01:01:43Z