Binaryweighted

Binaryweighted, often written binary-weighted, refers to a family of digital-to-analog converter (DAC) architectures in which each input bit controls a signal path weighted by a power of two. In a typical binary-weighted DAC, the weights are realized with resistors or current sources that are arranged so that the contribution of each bit is proportional to 2n, where n is the bit position (MSB to LSB). The outputs of the active branches are summed to produce the analog output.

Two common realizations are voltage-mode and current-mode binary-weighted DACs. In voltage-mode implementations, a set of resistors with values proportional to powers of two is switched to a reference voltage or ground, and the resulting voltages are summed at an op-amp summing node. In current-mode versions, each bit controls a current source that is switched into a summing node, with the total current converted to a voltage by an edge-preserving amplifier.

Advantages of binary-weighted DACs include conceptual simplicity and fast switching, making them straightforward to understand and implement for a small number of bits. However, they scale poorly in component count: a(n)-bit binary-weighted network ideally requires 2n components, and real-world mismatch in resistor values or switch on-resistance introduces gain and nonlinearity errors.

Due to these scaling challenges, binary-weighted architectures are less common for high-resolution DACs. Modern designs often use alternatives such as R-2R ladder networks or current-steering multipliers, which achieve higher bit counts with fewer components and better matching. Binary-weighted topologies are still encountered in educational contexts and some niche, low-to-mid resolution applications.

See also: digital-to-analog converter, resistor ladder DAC, R-2R ladder, current-steering DAC, multiplying DAC.