Equation 1 · Part 4 · Edge AI Electronics and Sensor Systems in Practice: An Advanced Technical Guide

Symbol P_i

\bar{P} = \sum_{i} f_i \, P_i

P_i

What this part means

the measured — not datasheet-typical — power draw in that state.

Its job in the formula

$P_i$ is an input to the expression that computes the quantity on the left.

Full expressionSymbol P_iArticle meaning

Where the article explains it

Here $f_i$ is the fraction of time the device spends in power state i (sleep, always-on monitoring, escalated inference, radio) and $P_i$ is the measured — not datasheet-typical — power draw in that state.

The passage around this formula

…shunt measurement campaign, even a short one, converts most of that stack into fact. Here $f_i$ is the fraction of time the device spends in power state i (sleep, always-on monitoring, escalated inference, radio) and $P_i$ is the measured — not datasheet-typical — power draw in that state. This formulation is worth writing out because it exposes the one lever that dominates every other design decision: since $f_{\text{sleep}}$ is normally close to one and $P_{\text{sleep}}$ is normally the smallest term, the average…

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

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Sources cited in the article section

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