15.12.1 Crystal Oscillator (XOSC) Characteristics

Digital Clock Characteristics

The following table describes the characteristics for the oscillator when a digital clock is applied on XIN.

Table 15-33. Digital Clock Characteristics
Symbol	Parameter	Min.	Typ.	Max.	Units
F_XIN	XIN clock frequency	-	-	24	MHz
DC_XIN	XIN clock duty cycle	40	50	60	%

Crystal Oscillator Characteristics

The following Table describes the characteristics for the oscillator when a crystal is connected between XIN and XOUT.

The user must choose a crystal oscillator where the crystal load capacitance C_L is within the range given in the Table. The exact value of C_L can be found in the crystal datasheet. The capacitance of the external capacitors (C_LEXT) can then be computed as follows:

C_LEXT = 2(C_L - C_STRAY - _SHUNT) ,

where C_STRAY is the capacitance of the pins and the PCB, and C_SHUNT is the shunt capacity of the crystal.

Table 15-34. Multi Crystal Oscillator Electrical Characteristics
Symbol	Parameter	Conditions	Min.	Typ.	Max.	Units
F_OUT	Crystal oscillator frequency		0.4	-	32	MHz
ESR	Crystal Equivalent Series Resistance - SF=3	F=0.4MHz, C_L=100pF XOSC, GAIN=0	-	-	5.6K	Ω
		F=2MHz, C_L=20pF XOSC,GAIN=0	-	-	416
		F=4MHz, C_L=20pF XOSC, GAIN=1	-	-	243
		F=8MHz, C_L=20pF XOSC, GAIN=2	-	-	138
		F=16MHz, C_L=20pF XOSC, GAIN=3	-	-	66
		F=32MHz, C_L=20pF XOSC, GAIN=4	-	-	56
C_XIN	Parasitic load capacitor		-	5.8	-	pF
C_XOUT	Parasitic load capacitor		-	3.2	-	pF
T_START	Startup time	F=2MHz, C_L=20pF XOSC, GAIN=0	-	14k	48k	Cycles
		F=4MHz, C_L=20pF XOSC, GAIN=1	-	6.8k	19.5k
		F=8MHz, C_L=20pF XOSC, GAIN=2	-	5.6k	13k
		F=16MHz, C_L=20pF XOSC, GAIN=3	-	6.8k	14.5k
		F=32MHz, C_L=20pF XOSC, GAIN=4	-	5.3K	9.6k

Note: (1) These values are based on characterization.

Table 15-35. Power Consumption⁽¹⁾
Symbol	Parameter	Conditions		Ta	Min.	Typ.	Max.	Units
I_DD	Current consumption	F=2MHz - CL=20pF XOSC,GAIN=0, VCC=3.3V	AGC=OFF	Max 85°C Typ 25°C	-	89	133	µA
		F=2MHz - CL=20pF XOSC,GAIN=0, VCC=3.3V	AGC=ON		-	82	130
		F=4MHz - CL=20pF XOSC,GAIN=1, VCC=3.3V	AGC=OFF		-	140	194
		F=4MHz - CL=20pF XOSC,GAIN=1, VCC=3.3V	AGC=ON		-	102	156
		F=8MHz - CL=20pF XOSC,GAIN=2, VCC=3.3V	AGC=OFF		-	243	313
		F=8MHz - CL=20pF XOSC,GAIN=2, VCC=3.3V	AGC=ON		-	166	232
		F=16MHz - CL=20pF XOSC,GAIN=3, VCC=3.3V	AGC=OFF		-	493	605
		F=16MHz - CL=20pF XOSC,GAIN=3, VCC=3.3V	AGC=ON		-	293	393
		F=32MHz - CL=20pF XOSC,GAIN=4, VCC=3.3V	AGC=OFF		-	1467	1777
		F=32MHz - CL=20pF XOSC,GAIN=4, VCC=3.3V	AGC=ON		-	651	1045

Note: (1) These values are based on characterization.