Oscillators and Clocks

Operating conditions:

• V_DD=3V, except where specified otherwise.

Table 1. 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 2. 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 3. 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 1. External Clock Waveform Characteristics

Table 4. 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	%