ZL30106_05 ZARLINK [Zarlink Semiconductor Inc], ZL30106_05 Datasheet - Page 32

• Manufacturer Part Number: ZL30106_05
• Description: SONET/SDH/PDH Network Interface DPLL
• Manufacturer: ZARLINK [Zarlink Semiconductor Inc]

contributes approximately 9 ppm to the frequency deviation. Consequently, capacitor tolerances and stray
capacitances have a major effect on the accuracy of the oscillator frequency.
The crystal should be a fundamental mode type - not an overtone. The fundamental mode crystal permits a simpler
oscillator circuit with no additional filter components and is less likely to generate spurious responses. A typical
crystal oscillator specification and circuit is shown in Table 8 and Figure 20 respectively.
6.3
The ZL30106 requires that the 3.3 V supply is not powered up after the 1.8 V supply. 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 supply fully first, then power up the 1.8 V supply
2. Power up the 3.3 V supply and the 1.8 V supply simultaneously, ensuring that the 3.3 V supply is never lower
than a few hundred millivolts below the 1.8 V supply (e.g., by using a schottky diode or controlled slew rate)
Power Up Sequence
1
2
3
4
5
6
ZL30106
Table 8 - 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 20 - Crystal Oscillator Circuit
OSCi
OSCo
1 MΩ
Zarlink Semiconductor Inc.
ZL30106
100 Ω
32
20 MHz
20 MHz
as required
fundamental
parallel
as required
50 Ω
1 µH
Data Sheet
.