title: How to improve accuracy of CMWX1ZZABZ-091 RTC (Real Time Clock)
body: <p>I'm using the B-L072Z-LRWAN1 with the CMWX1ZZABZ-091 LoRa® /Sigfox™ module (Murata)</p>
  
  <p>The internal RTC (real time clock) is inaccurate and I'm seeing 10 seconds loss per day for some modules. </p>
  
  <p>My question is, why could this be? Datasheet says 1.73 seconds / 20ppm for the LSE. The TXCO is 2ppm. How can I calibrate the RTC using TXCO? </p>
  
  <p>I know there is also temperature that influences the accuracy but I think that is in an insignificant range i.e. does not explain 10seconds /day.</p>