1 Abstract

The Excel-based tool allows users to estimate their thermal power based upon specified loadings for different components (compute cores and peripherals) of the system-on-chip (SoC). The tool allows the user to pre-populate the various fields (which components are used, and utilization of the major components) from a set of representative use cases. This gives a starting point from which a new use case can be customized to judge the power and loadings of their own use case. The tool provides a breakdown of thermal power at the junction temperature (Tj) entered, and it also provides a table of power delivery network (PDN) currents computed for this defined use case at Tj = 125°C or 105°C.⁽¹⁾

The tool gives two power estimates:

Thermal power estimate

• The time constant for heating or cooling an SoC is on the order of seconds or minutes. Because this is the primary use for the tool, the loadings should represent the average activity over a duration of seconds or minutes.

Peak / PDN estimate

• The time constant for peak current (power) is on the order of a microsecond. Though a use case (on average) may utilize a given component for say 70%, for windows of time that component will be at 100% utilization. The tool’s calculation for Peak / Power Delivery Network (PDN) estimates automatically increases the loading on key intellectual property (IP) that is enabled in order to create the PDN requirements.