3.1 Crystal Oscillator

The following table provides the crystal oscillator parameters for the ATWILC3000A.

Table 3-1. Crystal Oscillator Parameters
Parameter	Min.	Typ.	Max.	Unit
Crystal Resonant Frequency	—	26	—	MHz
Crystal Equivalent Series Resistance	—	50	150	Ω
Stability – Initial Offset⁽¹⁾	-100	—	100	ppm
Stability – Temperature and Aging	-20	—	20	ppm

Note:

Initial offset must be calibrated to maintain ±20 ppm in all operating conditions when including temperature and aging. This calibration is expected to be performed by the end user during their final production testing.

The block diagram in figure (a) shows how the internal crystal oscillator (XO) is connected to the external crystal. The XO has 5 pF internal capacitance on each terminal, XO_P and XO_N. To bypass the crystal oscillator with an external reference, an external signal capable of driving 5 pF can be applied to the XO_N terminal, as shown in figure (b).

Figure 3-1. Crystal Oscillator Connections

The following table provides the electrical and performance requirements for the external clock.

Table 3-2. Bypass Clock Specification
Parameter	Min.	Typ.	Max.	Unit	Comments
Oscillation Frequency	—	26	—	MHz	Must be able to drive 5 pF load at desired frequency
Voltage Swing	0.5	—	1.2	V_PP	Must be AC coupled
Stability – Temperature and Aging	-20	—	+20	ppm	—
Phase Noise	—	—	-130	dBc/Hz	At 10 kHz offset
Jitter (RMS)	—	—	<1	psec	Based on integrated phase noise spectrum from 1 kHz to 1 MHz