Understand the difference.

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

1

IEC

IEC open-collector buffer (rectangular form)

The underlined diamond inside the outline marks an output that can pull to a low level but needs an external pull-up to produce a high level. TI's public explanation describes this as suitable for a positive-logic wired-AND connection. The 1 qualifier makes the element non-inverting overall.

Drawing use

Schematic

Application

Logic & signals

Reference family

IEC / Manufacturer

Form evidence

1 element with the underlined-diamond open-circuit (L-type) 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 overlined diamond is the H-type open-emitter output, which sources current and needs a pull-down.

Full referenceAdd to legend

OC-BUF

Symbols

Open-collector buffer

Provides a logic output through a transistor pull-down stage requiring the documented external load or pull-up.

Drawing use

Schematic

Application

Logic & signals

Reference family

Manufacturer

A distinction that matters

An open collector can sink current under its limits; it does not actively drive the high state like a push-pull output.

Full referenceAdd to legend

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