zl30101 Zarlink Semiconductor, zl30101 Datasheet - Page 25

• Manufacturer Part Number: zl30101
• Description: T1/e1 Stratum 3 System Synchronizer
• Manufacturer: Zarlink Semiconductor

6.3
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)
Power Up Sequence
1
2
3
4
5
6
ZL30101
Table 6 - Typical Crystal Oscillator Specification
Frequency
Tolerance
Oscillation mode
Resonance mode
Load capacitance
Maximum series resistance
The 100 Ω resistor and the 1 µH inductor may improve
stability and are optional.
Figure 12 - Crystal Oscillator Circuit
OSCi
OSCo
1 MΩ
Zarlink Semiconductor Inc.
ZL30101
100 Ω
25
20 MHz
20 MHz
as required
fundamental
parallel
as required
50 Ω
1 µH
Data Sheet