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Question asked by Xiaoling Li on Aug 5, 2019
Latest reply on Aug 6, 2019 by Xiaoling Li

Hello, I just noticed that we designed LPC1778 ADC VREFP for 3.0V, isolated and separated from VDDA 3.3V, but in LPC1778 datasheet VREFP is defined as " This should be the same voltage as VDDA, but should be isolated to minimize noise and error." Does that means VREFP should be the same voltage LEVEL as VDDA? From UM10470 user manual document, our software engineer pointed another sentence to me that "Measurement range VSS to VREFP (typically 3 V; not to exceed VDDA voltage level)" which looks like to say it's ok that VREFP is 3.0V different from VDDA 3.3V. Please help for a clarification. Thanks.