Internal Oscillators

Table 1. Internal Oscillators Specifications(1)
Symbol Description Min. Typ. ✝ Max. Unit Conditions
fOSCHF OSCHF frequency

1(2)
2(2)
3(2)

MHz  
Precision calibrated OSCHF frequency

4
8
12
16
20
24

%CAL OSCHF tune step size 0.4 %  
tOSCHF_ST(3) OSCHF wake-up from sleep start-up time 24 30 μs

Device in Idle or Standby sleep mode,
VREGCTRL.PMODE = FULL

115 180 μs

Device in Power-Down sleep mode,
VREGCTRL.PMODE = AUTO

fOSC32K Internal OSC32K frequency 32.768 kHz  
tOSC32K_ST(3) OSC32K wake-up from sleep start-up time 950 1000 μs

Device in Power-Down sleep mode,
VREGCTRL.PMODE = AUTO

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

Notes:
  1. 1.To ensure these oscillator frequency tolerances, VDD and GND must be capacitively decoupled as close to the device as possible. 100 nF and 0.1 μF values in parallel are recommended.
  2. 2.These parameters are not calibrated.
  3. 3.Wake-up times are measured from the wake-up event to code execution.
Figure 1. Precision Calibrated OSCHF (4 MHz) Frequency Accuracy Over Device VDD and Temperature