topic Re: Relation of Sampling Rate to Tracking Rate in Digital Signal Controllers https://community.nxp.com/t5/Digital-Signal-Controllers/Relation-of-Sampling-Rate-to-Tracking-Rate/m-p/941225#M1695 <HTML><HEAD></HEAD><BODY><P>Referring to AN1942, device 56F80X. I am presuming that sampling frequency should be fast enough to detect the smallest change in the rotor speed. For a 12 bit RDC, speed updation rate is 244us for 60 rpm ( 1rps/4095). Similarly for 10 rps, updation rate would be 24.4us. Here sampling rate must be better that 24 us ( say 20us or 50KHz) to ensure that every delta changes are tracked correctly. Can you clarify if this is true? </P></BODY></HTML> Sat, 26 Oct 2019 09:22:51 GMT garimella 2019-10-26T09:22:51Z Relation of Sampling Rate to Tracking Rate https://community.nxp.com/t5/Digital-Signal-Controllers/Relation-of-Sampling-Rate-to-Tracking-Rate/m-p/941223#M1693 <HTML><HEAD></HEAD><BODY><P>Referring to AN3943. I have the following questions</P><P>1. How to convert the position information to digital. Will this conversion lead to truncation errors?</P><P>2. Does tracking rate depend on the sampling frequency. For eg For a 12 bit RDC, rollover takes place at 4095 counts/sec for 1 RPS. This means every LSB changes 244us. Could this mean that to detect this change in ATO sampling rate should be atleat 240us or 4Khz?</P></BODY></HTML> Thu, 03 Oct 2019 10:07:29 GMT https://community.nxp.com/t5/Digital-Signal-Controllers/Relation-of-Sampling-Rate-to-Tracking-Rate/m-p/941223#M1693 garimella 2019-10-03T10:07:29Z Re: Relation of Sampling Rate to Tracking Rate https://community.nxp.com/t5/Digital-Signal-Controllers/Relation-of-Sampling-Rate-to-Tracking-Rate/m-p/941224#M1694 <HTML><HEAD></HEAD><BODY><P>Hi, which device is this question related to?</P></BODY></HTML> Fri, 11 Oct 2019 08:30:16 GMT https://community.nxp.com/t5/Digital-Signal-Controllers/Relation-of-Sampling-Rate-to-Tracking-Rate/m-p/941224#M1694 davidtosenovjan 2019-10-11T08:30:16Z Re: Relation of Sampling Rate to Tracking Rate https://community.nxp.com/t5/Digital-Signal-Controllers/Relation-of-Sampling-Rate-to-Tracking-Rate/m-p/941225#M1695 <HTML><HEAD></HEAD><BODY><P>Referring to AN1942, device 56F80X. I am presuming that sampling frequency should be fast enough to detect the smallest change in the rotor speed. For a 12 bit RDC, speed updation rate is 244us for 60 rpm ( 1rps/4095). Similarly for 10 rps, updation rate would be 24.4us. Here sampling rate must be better that 24 us ( say 20us or 50KHz) to ensure that every delta changes are tracked correctly. Can you clarify if this is true? </P></BODY></HTML> Sat, 26 Oct 2019 09:22:51 GMT https://community.nxp.com/t5/Digital-Signal-Controllers/Relation-of-Sampling-Rate-to-Tracking-Rate/m-p/941225#M1695 garimella 2019-10-26T09:22:51Z