AN2586 Freescale Semiconductor / Motorola, AN2586 Datasheet - Page 12

• Manufacturer Part Number: AN2586
• Description: MPC8260 PowerQUICC II Family Power Distribution Trends
• Manufacturer: Freescale Semiconductor / Motorola

Previous Work Study
Previous Work Study
Also, the AC response to the 1 Amps sweeping AC at the current source of the load will resemble Figure 9.
Note how the damping resistance changed the AC response.
3.1.1 Analysis Summary
The analysis of the problem so far can be summarized as follows:
3.2 How to model the load?
Digital chips consists of millions of transistors. When we design our power system model we do not care
about the detailed model of the internal blocks of a chip. What we care about are the following:
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1. DC power drop is not taken into account across the network.
2. All vias models are ignored.
3. Very short power plane is assumed as well as no load, chip, package parasitic are included.
4. The approach of calculating the bypass capacitor did not take into account the accurate model of
5. The analysis dealt with the system as a pure circuit in terms of AC and transient., which is not
6. The effect of EMI circuit model behavior was not analyzed.
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bypass capacitor.
accurate because we have an inherent transmission line model that behaves differently for the
higher frequency signal transients.
How many power levels should we provide the chip, I/O, core, Analog, etc.?
What is the chip package parasitic?
MPC8260 PowerQUICC II Family Power Distribution Trends: A Survey
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
Figure 9.
MOTOROLA