Circuit and method for dynamically selecting circuit elements

Abstract

Techniques for dynamically selecting circuit elements to combat mismatches are described. In one design, an apparatus includes first, second, and third circuits. The first circuit receives input data and provides first signals that are asserted based on the input data, e.g., with thermometer decoding. The second circuit receives the first signals and provides second signals used to select circuit elements, e.g., current sources, capacitors, resistors, etc. The third circuit generates a control for the second circuit, and the second circuit maps the first signals to the second signals based on this control. In one design, the second circuit includes a set of multiplexers and a control circuit. The multiplexers provides the first signals, circularly rotated by an amount determined by the control, as the second signals. The control circuit accumulates control data (e.g., the input data, pseudo-random data, or a fixed value) with the current control value to obtain new control value.