Question

In a controlled current source with OP-Amp the circuit acts as:

• A. voltage amplifier.
• B. current-to-voltage converter.
• C. voltage-to-current converter.
• D. current amplifier.

Hint:

Remember the four basic types of amplifiers based on their input and output signals: - Voltage In, Voltage Out \(\rightarrow\) Voltage Amplifier - Current In, Voltage Out \(\rightarrow\) Transresistance Amplifier (Current-to-Voltage Converter) - Voltage In, Current Out \(\rightarrow\) Transconductance Amplifier (Voltage-to-Current Converter) - Current In, Current Out \(\rightarrow\) Current Amplifier

Answer 1

The Correct Option is C

Step 1: Understand the function of a controlled current source. A controlled current source is an electronic circuit that delivers a constant current to a load, where the value of this current is set by an input signal.
Step 2: Analyze the role of the Op-Amp in this application. In a typical Op-Amp based controlled current source (like a Howland current pump or a simple transistor-based design), an input voltage (\(V_{in}\)) is applied to one of the Op-Amp's inputs. The Op-Amp uses its high gain and feedback to adjust its output in such a way that the current flowing through the load (\(I_{out}\)) becomes directly proportional to the input voltage (\(I_{out} \propto V_{in}\)).
Step 3: Classify the circuit based on its input and output signals. The circuit takes a voltage as its input signal and produces a proportional current as its output signal. This is the definition of a voltage-to-current converter. Another name for this type of circuit is a transconductance amplifier.