https://community.nxp.com/t5/i-MX-Processors/IMX8m-mini-BD71847MWV-RTC/m-p/1169255#M163636 <P>Hi QiangweiBiao,</P> <P><SPAN class="tlid-translation translation"><SPAN title="">For i.MX8MM RTC, if you want to keep the RTC clock after shutdown, it needs 2 voltages and a 32.768K clock:</SPAN><BR /><SPAN title="">1. NVCC_SNVS_1V8</SPAN><BR /><SPAN title="">2. VDD_SNVS_0V8</SPAN><BR /><SPAN title="">3. CLK_32K_OUT</SPAN><BR /><SPAN title="">Therefore, you need to check whether the output of LDO1 and LDO2 is normal and whether the output of C32K_OUT is normal after you remove 5V.</SPAN><BR /><BR /><STRONG><SPAN title="">[In addition]</SPAN></STRONG><BR /><SPAN class="" title="">Considering that the power consumption of the RTC inside the CPU is larger than that of a separate RTC chip, it is strongly recommended that you use an independent RTC chip. NXP has many types of RTC chips, and you can choose one that meets your requirements.</SPAN></SPAN></P> <P>&nbsp;</P> <P><SPAN class="tlid-translation translation"><SPAN class="" title="">Have a nice day!</SPAN></SPAN></P> <P><SPAN class="tlid-translation translation"><SPAN class="" title="">B.R,</SPAN></SPAN></P> <P><SPAN class="tlid-translation translation"><SPAN class="" title="">weidong</SPAN></SPAN></P> Mon, 19 Oct 2020 02:58:25 GMT weidong_sun 2020-10-19T02:58:25Z https://community.nxp.com/t5/i-MX-Processors/IMX8m-mini-BD71847MWV-RTC/m-p/1169167#M163624 <P>I want to use the RTC of&nbsp;BD71847MWV&nbsp; ，so i change the SCH to the below one.But it seems do not work correctly.PLS&nbsp; HELP ME! Thanks a lot&nbsp;</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="qiaoweibiao_0-1602991527680.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127666iAAA39C880A09DAD9/image-size/medium?v=v2&amp;px=400" role="button" title="qiaoweibiao_0-1602991527680.png" alt="qiaoweibiao_0-1602991527680.png" /></span></P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="qiaoweibiao_1-1602991570371.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127667iCA131D92E816A88D/image-size/medium?v=v2&amp;px=400" role="button" title="qiaoweibiao_1-1602991570371.png" alt="qiaoweibiao_1-1602991570371.png" /></span></P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="qiaoweibiao_2-1602991731744.png" style="width: 400px;"><img src="https://community.nxp.com/t5/image/serverpage/image-id/127668i9091FBC49EC2C4D5/image-size/medium?v=v2&amp;px=400" role="button" title="qiaoweibiao_2-1602991731744.png" alt="qiaoweibiao_2-1602991731744.png" /></span></P><P>&nbsp;</P><P>&nbsp;</P><P>&nbsp;</P> Sun, 18 Oct 2020 03:29:08 GMT https://community.nxp.com/t5/i-MX-Processors/IMX8m-mini-BD71847MWV-RTC/m-p/1169167#M163624 qiaoweibiao 2020-10-18T03:29:08Z https://community.nxp.com/t5/i-MX-Processors/IMX8m-mini-BD71847MWV-RTC/m-p/1169255#M163636 <P>Hi QiangweiBiao,</P> <P><SPAN class="tlid-translation translation"><SPAN title="">For i.MX8MM RTC, if you want to keep the RTC clock after shutdown, it needs 2 voltages and a 32.768K clock:</SPAN><BR /><SPAN title="">1. NVCC_SNVS_1V8</SPAN><BR /><SPAN title="">2. VDD_SNVS_0V8</SPAN><BR /><SPAN title="">3. CLK_32K_OUT</SPAN><BR /><SPAN title="">Therefore, you need to check whether the output of LDO1 and LDO2 is normal and whether the output of C32K_OUT is normal after you remove 5V.</SPAN><BR /><BR /><STRONG><SPAN title="">[In addition]</SPAN></STRONG><BR /><SPAN class="" title="">Considering that the power consumption of the RTC inside the CPU is larger than that of a separate RTC chip, it is strongly recommended that you use an independent RTC chip. NXP has many types of RTC chips, and you can choose one that meets your requirements.</SPAN></SPAN></P> <P>&nbsp;</P> <P><SPAN class="tlid-translation translation"><SPAN class="" title="">Have a nice day!</SPAN></SPAN></P> <P><SPAN class="tlid-translation translation"><SPAN class="" title="">B.R,</SPAN></SPAN></P> <P><SPAN class="tlid-translation translation"><SPAN class="" title="">weidong</SPAN></SPAN></P> Mon, 19 Oct 2020 02:58:25 GMT https://community.nxp.com/t5/i-MX-Processors/IMX8m-mini-BD71847MWV-RTC/m-p/1169255#M163636 weidong_sun 2020-10-19T02:58:25Z https://community.nxp.com/t5/i-MX-Processors/IMX8m-mini-BD71847MWV-RTC/m-p/1169299#M163644 Mon, 19 Oct 2020 04:04:01 GMT https://community.nxp.com/t5/i-MX-Processors/IMX8m-mini-BD71847MWV-RTC/m-p/1169299#M163644 qiaoweibiao 2020-10-19T04:04:01Z