Symbol barP
barP is part of the quantity the equation computes from the expression on the right.
Read this term in its guide →Published equation contexts
Why this formula appears here
The third reason is that measurement itself has a cost and a failure mode. A current-sense shunt clamped around the supply rail is the standard way to verify what a design is actually drawing, as opposed to what its datasheet implies, and the discipline of doing this at multiple points in the duty cycle — sleep, wake-trigger evaluation, full inference, radio transmission — is what turns a power budget from arithmetic into an engineering artifact someone can defend. A budget built only from datasheet typical-current figures, without a bench measurement at each state, is analysis built on unverified vendor numbers stacked several layers deep; a single shunt measurement campaign, even a short…
Read the representative guide
Symbol i
i appears in the bound of this sum. The bound states where the repeated operation starts, ends, or which values it includes.
Read this term in its guide →Symbol f_i
the fraction of time the device spends in power state i (sleep, always-on monitoring, escalated inference, radio).
Read this term in its guide →Symbol P_i
the measured — not datasheet-typical — power draw in that state.
Read this term in its guide →Starting index or lower bound: i
This label says where the repeated addition, multiplication, or accumulation starts. Read its value or condition together with the article’s description of the index.
Read this term in its guide →How to interpret it
Read it with the definitions, units, and assumptions supplied by the article.
Research cited beside this formula
Published contexts (1)
A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.
Equation 1 · Edge AI & Electronics
Edge AI Electronics and Sensor Systems in Practice: An Advanced Technical Guide
This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.
The third reason is that measurement itself has a cost and a failure mode. A current-sense shunt clamped around the supply rail is the standard way to verify what a design is actually drawing, as opposed to what its datasheet implies, and the discipline of doing this at multiple points in the duty cycle — sleep, wake-trigger evaluation, full inference, radio transmission — is what turns a power budget from arithmetic into an engineering artifact someone can defend. A budget built only from datasheet typical-current figures, without a bench measurement at each state, is analysis built on unverified vendor numbers stacked several layers deep; a single shunt measurement campaign, even a short…
Meanings in this article
- : the fraction of time the device spends in power state i (sleep, always-on monitoring, escalated inference, radio).
- : the measured — not datasheet-typical — power draw in that state.