Oscillators and Clocks

Operating conditions:
Table 1. Internal Oscillator (OSC20M) Characteristics
Symbol Description Condition Min. Typ. Max. Unit
fOSC20M Accuracy with 16 MHz and 20 MHz frequency selection relative to the factory-stored frequency value

Factory calibrated
VDD = 3V(1)

T = [0, 70]°C,
VDD = [1.8, 4.5]V(3)

-2.0 - 2.0 %

Factory calibrated
VDD = 5V(1)

T = [0, 70]°C,
VDD = [4.5, 5.5]V(3)

-2.0 - 2.0
Accuracy with 16 MHz and 20 MHz frequency selection Factory calibrated T = 25°C, 3.0V -3.0 - 3.0 %

T = [0, 70]°C,
VDD = [1.8, 3.6]V(3)

-4.0 - 4.0
Full operation range(3) -5.0 - 5.0
fCAL User calibration range OSC20M(2) = 16 MHz   14.5 - 17.5 MHz
OSC20M(2) = 20 MHz   18.5 - 21.5
%CAL Calibration step size   - 1.5 - %
DC Duty cycle   - 50 - %
TStart Start-up time Within 2% accuracy   - 8 - µs
Notes:
  1. 1.See the description of OSC20M on calibration.
  2. 2.Oscillator frequencies above speed specification must be divided so that the CPU clock always is within specification.
  3. 3.These values are based on characterization and not covered by production test limits.
Table 2. 32.768 kHz Internal Oscillator (OSCULP32K) Characteristics
Symbol Description Condition Min. Typ. Max. Unit
fOSCULP32K Accuracy Factory calibrated T = 25°C, 3.0V -3 - 3 %

T = [0, 70]°C,
VDD = [1.8,  3.6]V(1)

-10 - 10
Full operation range(1) -30 - 30
DC Duty cycle     - 50 - %
TStart Start-up time     - 250 - µs
Note:
  1. 1.These values are based on characterization and not covered by production test limits.
Figure 1. External Clock Waveform Characteristics
Table 3. External Clock Characteristics
Symbol Description Condition VDD = [1.8, 5.5]V VDD = [2.7, 5.5]V VDD = [4.5, 5.5]V Unit
Min. Max. Min. Max. Min. Max.
fCLCL Frequency 0 5.0 0.0 10.0 0.0 20.0 MHz
tCLCL Clock period 200 - 100 - 50 - ns
tCHCX High time 80 - 40 - 20 - ns
tCLCX Low time 80 - 40 - 20 - ns