Signal conversion roles – does a D/A (digital-to-analog) converter convert physical analog variables (e.g., temperature) into digital numbers, or is that the role of an A/D converter?

Introduction / Context:
In mixed-signal systems, it is essential to distinguish between the directions of conversion. Sensors produce analog voltages or currents proportional to physical quantities such as temperature, pressure, or light. Understanding whether an ADC or a DAC performs the conversion to digital numbers avoids architectural mistakes.

Given Data / Assumptions:

• D/A (DAC) converts digital codes into analog voltages or currents.
• A/D (ADC) converts analog signals into digital codes.
• Sensors typically feed ADCs; DACs typically drive actuators or setpoints.

Concept / Approach:
The directionality is clear: a DAC takes a digital input word and produces a corresponding analog output. An ADC takes an analog input and produces a digital representation. Therefore, converting temperature (an analog variable sensed as a voltage/current) into a digital quantity is the role of the ADC, not the DAC. The statement that a D/A converter changes temperature variations into digital quantities is incorrect.

Step-by-Step Solution:

Verification / Alternative check:
Block diagrams in microcontroller datasheets show sensors feeding ADC inputs and DAC outputs driving actuators, VCO controls, or audio lines—supporting the directional roles.

Why Other Options Are Wrong:
Calling it “Correct” reverses definitions; flash is an ADC architecture and unrelated here; sensor linearization and reference choices do not change DAC vs ADC roles.

Common Pitfalls:
Mixing up acronyms under time pressure; assuming any converter can work both ways—it cannot without redesign; each device is directional.

Final Answer:
Incorrect