Strict Threshold Three-Row Scan - Electronic Circuits II Step by Step

Below, equal, and above threshold produce different ideal switch decisions. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

The threshold rule is strict

The ideal switch closes only when the measured voltage is above the threshold. Equal to the threshold is not above it.

\text{closed only if }V_m>V_{\text{threshold}}

Below, equal, and above are different rows

The measured value changes while the threshold stays fixed. The decision column is derived from the strict comparison.

\begin{array}{c|c|c}V_m&V_{\text{threshold}}&\text{decision}\\0\ \text{V}&1\ \text{V}&LOW\\1\ \text{V}&1\ \text{V}&LOW\\2\ \text{V}&1\ \text{V}&HIGH\\\end{array}

Equal is still low for a strict above-threshold gate

For the rendered row, measured voltage and threshold are both 1 volt, so the ideal switch stays open.

1\ \text{V}=1\ \text{V}\Rightarrow \text{LOW}