37.9 Oscillators and Clocks

Operating conditions:
  • VDD=3V, except where specified otherwise.
Table 37-11. 20MHz Internal Oscillator (OSC20M) Characteristics
Symbol Description Condition Min. Typ. Max. Unit
fOSC20M Accuracy with 16MHz Frequency Selection Factory calibrated T=25°C, 3.0V TBD ±1.5 TBD %
T=[0, 70]°C, VDD=[1.8, 3.6]V TBD ±2 TBD
Full operation range TBD ±3 TBD
Accuracy with 20MHz Frequency Selection Factory calibrated T=25C, 3.0V TBD ±1.5 TBD
T=[0, 70]°C, VDD=[1.8, 3.6]V TBD ±2 TBD
Full operation range TBD ±3 TBD
Accuracy with 16MHz Frequency Selection with factory-stored frequency error value Factory calibrated VDD=3V(1) T=[0, 70]°C, VDD=[1.8, 4.5]V TBD ±1.5 TBD %
Factory calibrated VDD=5V(1) T=[0, 70]°C, VDD=[4.5, 5.5]V TBD ±1.5 TBD
Accuracy with 20MHz Frequency Selection with factory-stored frequency error value Factory calibrated VDD=3V(1) T=[0, 70]°C, VDD=[1.8, 4.5]V TBD ±1.5 TBD
Factory calibrated VDD=5V(1) T=[0, 70]°C, VDD=[4.5, 5.5]V TBD ±1.5 TBD
fCAL User calibration range OSC16M(2) 14.5 17.5 MHz
OSC20M(2) 18.5 21.5 MHz
%CAL Calibration step size - 1.5 - %
DC Duty cycle - 50 - %
Tstart Start-up time Within 2% accuracy - 8 - µs
Note:
  1. See also description of OSC20M on calibration.
  2. Oscillator Frequencies above speed specification must be divided so that CPU clock always is within specification.
Table 37-12. 32.768kHz Internal Oscillator (OSCULP32K) Characteristics
Symbol Description Condition Condition Min. Typ. Max. Unit
fOSCULP32K Accuracy Factory calibrated T=25°C, 3.0V TBD ±2 TBD %
T=[0, 70]°C, VDD=[1.8, 3.6]V -10 ±5 +10
Full operation range -30 ±10 +30
DC Duty cycle - 50 - %
Tstart Start-up time - 250 - µs
Table 37-13. 32.768kHz External Crystal Oscillator (XOSC32K) Characteristics
Symbol Description Condition Min. typ Max. Unit
Fout Frequency - 32.768 - kHz
Tstart Startup time CL=7.5pF - 300 - ms
CL=12.5pF - TBD -
CL Crystal load capacitance 7.5 - 12.5 pF
CTOSC1 Parasitic capacitor load - 5.5 - pF
CTOSC2 - 5.5 - pF
ESR Equivalent Series Resistance - Safety Factor=3 CL=7.5pF - - 80 kΩ
CL=12.5pF - - 40
Figure 37-2. External Clock Waveform Characteristics
Table 37-14. 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
tCLCH Rise Time - 2.0 - 1.6 - 0.5 µs
tCHCL Fall Time - 2.0 - 1.6 - 0.5 µs
ΔtCLCL Change in period from one clock cycle to the next - 2 - 2 - 2 %