Event - Driven Modeling of Cross-Coupling in Phase-Locked Loops Through Supply Paths

The demand for reliable, low-cost, low-power communication is permanently increasing, forcing higher complexity and integration density in modern Systems-on-Chip (SoCs). This results in additional effects such as coupling and noise propagation that need to be considered for pre-tapeout top-level chip verification. Traditional AMS simulations are not powerful enough to handle such test cases in an appropriate time frame. Therefore event-driven AMS and RF modeling is proposed that can also consider noise sources in an efficient way especially on the power supply that is connected to all blocks. The supply net provides differently detailed descriptions of the net status, while the blocks choose the appropriate one to efficiently model their transfer characteristics. As Phase-Locked Loops (PLLs) are critical in communication circuits, with their performance directly effecting the RF output, a PLL serves as an example to show the model building process and system level analysis.