A systematic design procedure for square-root-domain circuits based on the signal flow graph approach

A new systematic design procedure for square-root-domain (√x-domain) circuits, which is based on the signal flow graph (SFG) synthesis approach, is introduced in this paper. The SFG of the prototype system is modified, using a proposed set of operators, in such a way that √x-domain building blocks could be used for the corresponding implementations. For this purpose, new √x-domain integrator circuits have been proposed which were constructed from new current-mode geometric-mean and multiplier/divider circuits. The main advantages of the proposed circuits are the accuracy due to immunity to the body effect, low circuit complexity and potential for low-voltage operation. As an example, a fifth-order Chebyshev low-pass filter was designed using the proposed technique. Simulation results confirm the validity of the proposed design technique and the high performance of the proposed circuits.