Sunday, July 15, 2012

UART clock tolerance

The clock tolerance issue is analyzed in the Maxim App Notes 2141.  Assuming 16-clock sampling scheme, the tolerance is +/-5 clocks for nominal and +/-3 clocks for worse cases.  From the start bit to the middle of the stop bit with 8-bit data, the total is 152 clocks.  The percentage tolerance is +/-3.3% and +/-2%.