Practice Flashcards
Flip to reveal answersDefine an operational amplifier.
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 4 Flashcards — Operational amplifiers
Sign up free to track progress and get spaced-repetition review schedules.
Question
Define an operational amplifier.
Answer
A high-gain voltage amplifier with a non-inverting input (+), an inverting input (−) and a single output. It amplifies the difference between its two inputs.
Question
Why does an op-amp need feedback around it?
Answer
Its open-loop gain is about 100,000, so a millivolt of difference saturates the output. Two feedback resistors return part of the output to the inverting input, and their ratio sets a usable gain.
Question
Why do differential inputs matter for a sensor?
Answer
Interference picked up along a cable and drift with temperature appear on both inputs equally, so amplifying the difference rejects them. That is why sensor leads run as pairs.
Question
Where is an op-amp used in an IoT product?
Answer
Between the sensor and the microcontroller in a smart thermostat, connected doorbell, fitness band or kitchen scale — amplifying and filtering a millivolt signal so the converter can read it.
Read the notes
Full study notes for Operational amplifiers
Topic 3.4 hub
Electronic systems
More from Topic 3.4
All flashcards in this topic
Design Technology exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free