Which device is used to convert a binary number to a 7-segment display format?

A decoder is the appropriate device for converting a binary number to a 7-segment display format because it takes binary input and translates it into a corresponding output that controls the segments of the display. In a typical setup, a 4-bit binary number can represent values from 0 to 15, but only values from 0 to 9 are usually needed for a decimal display. The decoder directly activates the necessary segments of the 7-segment display, allowing it to visually represent the input binary number.

This operation involves the decoder interpreting the binary inputs and selectively enabling the segments (labeled a through g) that form the desired numeral. Each unique binary input corresponds precisely to a specific pattern on the display, highlighting the functionality of the decoder in interfacing with the 7-segment format.

Other devices mentioned serve different purposes: encoders convert information from one format to another, segment drivers are typically used to control the brightness and power used for displaying outputs, and multiplexers select one of many input signals and forward it to a single output line, but they are not focused on converting binary digits into the specific graphical representation needed for a 7-segment display.