Power Integrity (PI) is a major noise factor
Trend in IC and PI Issue Trends in IC and PI issues
Since the IC chip has become faster at low voltage, power noise problems have been increasing.
On the power distribution network (PDN) from battery, the IC consumes the current and causes voltage drop relevant to the IC malfunction problem. Lower impedance in the PDN is desired to avoid the noise problem, but even though the latest IC chips consume less voltage, the current speed is very fast (see figure: Trends in IC).
In the latest ICs, switching current peak increases constantly, and power voltage drops at the same time (see figure below).
PI problems can sometimes cause an unmatched clock rhythm because of this voltage fluctuation. To avoid this problem, capacitors need to be placed around critical ICs to achieve impedance.
PIStream can eliminate input impedance, transfer impedance, and DC relevant to voltage drop at the design phase, enabling you to visually consider how to fix the problem. By doing this at the design phase, you will be able to save both time and money in your PCB development.
Jitter generation caused by voltage fluctuation
Reference clock jitter and analog voltage fluctuation can degrade eye patterns.
Since jitter is caused by the PI issue, suppressing jitter using just SI tools can only go so far. The following figure shows the effect before and after a filter is added for power IC. After the filter is added, the eye diagram becomes clearer and has a wider eye opening.
Verifying Analysis Accuracy
The following graph compares the results of an actual measurement (blue line) and PIStream calculation (pink line). S21 calculated by PIStream and S21 by actual measurement shows a correlation up to 3 GHz. When PIStream cannot calculate S21, it uses an output analysis model.
- *EMIStream and PIStream are both registered trademarks or trademarks of NEC Solution Innovators, Ltd. in the United States and/or other countries.