Intel 1.80 GHz RH80532NC033256 Datenbogen
Produktcode
RH80532NC033256
Mobile Intel
®
Celeron
®
Processor (0.13 µ) in
Micro-FCBGA and Micro-FCPGA Packages Datasheet
96 Datasheet
298517-006
Appendix A. PLL RLC Filter Specification
A1. Introduction
All Mobile Intel Celeron Processors have internal PLL clock generators, which are analog in nature and
require quiet power supplies for minimum jitter. Jitter is detrimental to a system; it degrades external
I/O timings as well as internal core timings (i.e. maximum frequency). The PLL RLC filter
specifications for the Mobile Intel Celeron Processor are the same as those for the mobile Intel Pentium
III Processor-M. The general desired topology is shown in Figure 2. Excluded from the external circuitry
are parasitics associated with each component.
require quiet power supplies for minimum jitter. Jitter is detrimental to a system; it degrades external
I/O timings as well as internal core timings (i.e. maximum frequency). The PLL RLC filter
specifications for the Mobile Intel Celeron Processor are the same as those for the mobile Intel Pentium
III Processor-M. The general desired topology is shown in Figure 2. Excluded from the external circuitry
are parasitics associated with each component.
A2. Filter
Specification
The function of the filter is two fold. It protects the PLL from external noise through low-pass
attenuation. It also protects the PLL from internal noise through high-pass filtering. In general, the low-
pass description forms an adequate description for the filter.
attenuation. It also protects the PLL from internal noise through high-pass filtering. In general, the low-
pass description forms an adequate description for the filter.
The AC low-pass specification, with input at V
CCT
and output measured across the capacitor, is as
follows:
• < 0.2-dB gain in pass band
• < 0.5-dB attenuation in pass band < 1 Hz (see DC drop in next set of requirements)
• 34-dB attenuation from 1 MHz to 66 MHz
• 28-dB attenuation from 66 MHz to core frequency
• The filter specification (AC) is graphically shown in Figure 32.
• < 0.5-dB attenuation in pass band < 1 Hz (see DC drop in next set of requirements)
• 34-dB attenuation from 1 MHz to 66 MHz
• 28-dB attenuation from 66 MHz to core frequency
• The filter specification (AC) is graphically shown in Figure 32.
Other requirements:
• Use a shielded type inductor to minimize magnetic pickup
• The filter should support a DC current of at least 30 mA
• The filter should support a DC current of at least 30 mA
• The DC voltage drop from V
CCT
to PLL1 should be less than 60 mV, which in practice implies
series resistance of less than 2
Ω. This also means that the pass band (from DC to 1 Hz)
attenuation below 0.43 dB for V
CCT
= 1.25 V.