Improper Termination of Unused Sections

4.2.1 Common Mistake Number 1 – Improper Termination of Unused Sections One of the easiest ways to unintentionally misapply an op amp is to misapply unused sections of a multiple section IC. Figure 10 shows the most common ways designers connect unused sections. BRAIN - DEAD!!! NEVER! NO! JUST - AS - BAD! GOOD SMART +RAIL ZERO OPEN OPEN ZERO Figure 10. Different Ways of Dealing With Unused Op Amp Sections Many designers know how to properly terminate unused digital inputs, hooking them to the supply or ground. This section demonstrates techniques Texas Instruments applications have actually seen, and they have been given titles: • Brain-dead: This is a common mistake. Designers will assume an op amp is like an audio amp at home, and just leave unused inputs unconnected. This is the worst thing that can be done to an op amp. An open-loop op amp saturates to one voltage rail or the other. Because the inputs are floating, and picking up noise, the output of the op amp switches from rail-to-rail, sometimes at unpredictable high frequencies.

На изображении показана страница технического руководства Texas Instruments о неправильном подключении неиспользуемых секций операционного усилителя. Схемы помечены от «BRAIN - DEAD!!!» до «SMART», а текст объясняет, что оставлять входы неподключёнными — худшая ошибка, из-за которой усилитель может переключаться на непредсказуемых частотах. Шутка строится на саркастичной классификации инженерных решений и реакции «официальный мануал» на очевидно нелепую ошибку. EN: The image shows a page from a Texas Instruments technical manual about improperly connecting unused sections of an operational amplifier. The diagrams are labeled from “BRAIN - DEAD!!!” to “SMART,” and the text explains that leaving inputs unconnected is the worst mistake because the amplifier may switch at unpredictable frequencies. The joke comes from the sarcastic classification of engineering solutions and the reaction of presenting an obvious mistake as an “official manual.”

• @pokupkabitka / 50393 2025-05-19