Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

IEC

IEC three-state output qualifier

The three-state qualifier is a small triangle pointing downwards, drawn inside the outline next to the output. It says the output has a third, high-impedance state in addition to high and low. The output is controlled by an EN input or by EN dependency.

Drawing use: Schematic
Application: Logic & signals
Reference family: IEC / Manufacturer
Form evidence: Small downward-pointing triangle inside the outline at the output. Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier.

A distinction that matters

The open-circuit diamond indicates a stage that is off in one level, not a controlled high-impedance state.

Full reference

IEC

IEC three-state buffer (rectangular form)

The three-state buffer is drawn as a 1 element with a small downward triangle inside the outline next to the output, and an EN input. When EN is at its internal 1 state the output follows the input; at its internal 0 state the output goes to its external high-impedance state while the internal logic state is retained.

Drawing use: Schematic
Application: Logic & signals
Reference family: IEC / Manufacturer
Form evidence: 1 element with EN input and inverted-triangle three-state output qualifier. Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.

A distinction that matters

An open-circuit output uses a diamond qualifier and has no high-impedance logic state of its own; the three-state triangle is different.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.