35.10.1 Internal Oscillators

Table 35-10. Internal Oscillators Specifications(1)
Operating Conditions:
  • VDDIO = VDDMIN to VDDMAX
  • Temperature = -40 °C to +125 °C
SymbolDescriptionMin.Typ. ✝Max.UnitConditions
fOSCHFPrecision-calibrated OSCHF frequency16MHzOSCCFG.OSCHFFRQ = 0x1
20MHzOSCCFG.OSCHFFRQ = 0x0
fCALFrequency tune range±10%OSCCFG.OSCHFFRQ = 0x1
±10%OSCCFG.OSCHFFRQ = 0x0
%CALOSCHF tune step size0.4%
EOSCHF_TOTALTotal error with 16 MHz frequency selection(3)-22%

TA = 25°C,

VDD = 3.0V

-44%Full operation range
Total error with 20 MHz frequency selection(4)-1.51.5%

TA = 25°C,

VDD = 3.0V

-33%Full operation range
DOSCHFOSCHF Duty cycle50%
tOSCHF_ST(2) OSCHF Start-up time10μsWithin 2% accuracy
fOSC32KInternal OSC32K frequency32.768kHz
EOSC32K_TOTALTotal error from target frequency-44%

TA = 25°C,

VDD = 3.0V

-1515%TA < 85°C
-2020%Full operation range
DOSC32KOSC32K duty cycle50%
tOSC32K_ST(2) OSC32K Start-up time220μs

Data in the “Typ.” column is measured at TA = 25°C and VDD = 3.0V unless otherwise specified. These parameters are not tested and are for design guidance only.

Note:
  1. To ensure these oscillator frequency tolerances, VDD and GND must be decoupled as close to the device as possible. 100 nF and 0.1 μF values in parallel are recommended.
  2. Wake-up times are measured from the wake-up event to code execution.
  3. The CLKCTRL.OSCHFTUNE is loaded from the Signature Row OSCHF16TUNE.

  4. The CLKCTRL.OSCHFTUNE is loaded from the Signature Row OSCHF20TUNE.