ZL30101 Data Sheet
25
Zarlink Semiconductor Inc.
Figure 12 - Crystal Oscillator Circuit
6.3 Power Up Sequence
The ZL30101 requires that the 3.3 V rail is not powered-up later than the 1.8 V rail. This is to prevent the risk of
latch-up due to the presence of parasitic diodes in the IO pads.
Two options are given:
1. Power up the 3.3 V rail fully first, then power up the 1.8 V rail
2. Power up the 3.3 V rail and 1.8 V rail simultaneously, ensuring that the 3.3 V rail voltage is never lower than the
1.8 V rail voltage minus a few hundred millivolts (e.g., by using a schottky diode or controlled slew rate)
1 Frequency 20 MHz
2 Tolerance as required
3 Oscillation mode fundamental
4 Resonance mode parallel
5 Load capacitance as required
6 Maximum series resistance 50 Ω
Table 6 - Typical Crystal Oscillator Specification
OSCo
1 MΩ
20 MHz
ZL30101
OSCi
100 Ω
1 μH
The 100 Ω resistor and the 1 μH inductor may improve
stability and are optional.
