36.9 Oscillators and Clocks
Operating conditions:
- VDD = 3V, except where specified otherwise
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 |
T = [0, 70]°C, | -2.0 | - | 2.0 | % |
Factory calibrated |
T = [0, 70]°C, | -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, | -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 |
Note:
- See the description of OSC20M on calibration.
- Oscillator frequencies above speed specification must be divided so that the CPU clock always is within specification.
- These values are based on characterization and not covered by production test limits.
Symbol | Description | Condition | Min. | Typ. | Max. | Unit | |
---|---|---|---|---|---|---|---|
fOSCULP32K | Accuracy | Factory calibrated | T = 25°C, 3.0V | -3 | - | 3 | % |
T = [0, 70]°C, | -10 | - | 10 | ||||
Full operation range(1) | -30 | - | 30 | ||||
DC | Duty cycle | - | 50 | - | % | ||
TStart | Start-up time | - | 250 | - | µs |
Note:
- These values are based on characterization and not covered by production test limits.
Symbol | Description | Condition | Min. | Typ. | Max. | Unit |
---|---|---|---|---|---|---|
Fout | Frequency | - | 32.768 | - | kHz | |
TStart | Start-up time | CL = 7.5 pF | - | 300 | - | ms |
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 = 7.5 pF | - | - | 80 | kΩ |
CL = 12.5 pF | - | - | 40 |
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 |