Circuit identification — The shown network (weighted currents summed via equal 2R branches and R returns) corresponds to which classic data-converter circuit?

Introduction / Context:
Two common DAC realizations are the binary-weighted-resistor DAC and the R/2R ladder DAC. Textbook schematics often show a repetitive ladder using only two resistor values (R and 2R), with digital switches steering nodes either to a reference or ground. Recognizing this pattern is essential in converter identification questions, even when a figure is summarized in text.

Given Data / Assumptions:

• The circuit shows repeating R–2R sections feeding a summing node.
• Each bit controls a switch connecting a ladder tap to V_ref or ground.
• An op-amp may be used as a transimpedance stage to produce V_out.

Concept / Approach:
The R/2R ladder uses only two resistor values, simplifying matching and scaling. Each additional bit adds one identical section, making the design highly modular. Equal 2R branches ensure that each bit contributes a precisely halved weight relative to the next more significant bit without requiring exponentially small or large resistor values.

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