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S08P - ICS trimming resolution, in datasheet, is correct ?

Question asked by José Antonio Berruezo on Feb 15, 2016
Latest reply on Feb 17, 2016 by José Antonio Berruezo

Hi,

All documentation I have consulted about 'S08 5.5V Series - ICS trimming' indicates that 'Trim Resolution' is :

    +/-0.2% typ. of untrimmed frequency (8bit, SCFTRIM not in use)

    +/-0.1% typ. of untrimmed frequency (9 bit, SCFTRIM in use)

 

But S08PA16 Reference Manual, pag. 186, 'Example 8.3.1.1', says :

 

    TRIM_VALUE_39K0625HZ; /* FLL output 20MHz, TRIM_VALUE_39K0625HZ is ~0x50 typically

 

    TRIM_VALUE_31K25HZ; /* FLL output 16MHz, TRIM_VALUE_31K25HZ is ~0x90 typically */

 

With these data, and assuming untrimmed frequency = 36kHz typ., I can calculate :

 

     (39.0625 kHz - 31.25 kHz)

     -----------------------------------

              (0x50 - 0x90)

------------------------------------------- x100 = 0.34% typ of untrimmed frequency (8 bit)

                    36 kHz

 

 

 

This calculated 0.34% is slightly worse than the specified 0.2%. 

Am I correct ? Is datasheet wrong ?

 

Thank you very much for your assistance

 

JoseAntonio Berruezo

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