Crystal Oscillator Characteristics

The following table describes the characteristics for the oscillator when a crystal is connected between XIN and XOUT as shown in Figure 1. The user must choose a crystal oscillator where the crystal load capacitance C_Lis 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:

CLEXT=2CL+−CSTRAY−CSHUNT

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

Figure 1. Oscillator Connection

Table 1. Multi Crystal Oscillator Electrical Characteristics ⁽¹⁾
Symbol	Parameter	Conditions	Min.	Typ.	Max	Units
Fout	Crystal oscillator frequency		0.4	-	32	MHz
ESR	Crystal Equivalent Series Resistance - SF = 3	F = 0.455 MHz CL = 100pF XOSC.GAIN = 0	-	-	443	Ω
		F = 2MHz CL=20pF XOSC.GAIN=0	-	-	383
		F = 4MHz CL=20pF XOSC.GAIN=1	-	-	218
		F = 8MHz CL=20pF XOSC.GAIN=2	-	-	114
		F = 16MHz CL=20pF XOSC.GAIN=3	-	-	61
		F = 32MHz CL=18pF XOSC.GAIN=4	-	-	41
Cxin	Parasitic load capacitor		-	5.9	-	pF
Cxout	Parasitic load capacitor		-	3.1	-	pF
Tstart	Startup time	F = 2MHz CL=20pF XOSC.GAIN=0	-	12.3	48	Cycles
		F = 4MHz CL=20pF XOSC.GAIN=1	-	8.2	30.1
		F = 8MHz CL=20pF XOSC.GAIN=2	-	6.2	19.9
		F = 16MHz CL=20pF XOSC.GAIN=3	-	10.8	30.1
		F = 32MHz CL=18pF XOSC.GAIN=4	-	8.7	20.1

These are based on characterization.

Table 2. Power Consumption ⁽¹⁾
Symbol	Parameters	Conditions	Ta	Typ.	Max	Units
IDD	Current consumption	F = 2MHz CL=20pF XOSC.GAIN=0 VDD = 5.0V AGC=OFF	Max 85°C Typ 25°C	150	202	µA
		AGC=ON		138	192
		F = 4MHz CL=20pF XOSC.GAIN=1 VDD = 5.0V AGC=OFF		220	288
		AGC=ON		175	260
		F = 8MHz CL=20pF XOSC.GAIN=2 VDD = 5.0V AGC=OFF		350	416
		AGC=ON		247	321
		F = 16MHz CL=20pF XOSC.GAIN=3 VDD = 5.0V AGC=OFF		663	843
		AGC=ON		429	699
		F = 32MHz CL=20pF XOSC.GAIN=4 VDD = 5.0V AGC=OFF		1975	2329
		AGC=ON		874	1181