Simple square-root extractor using op amps

This paper presents the simple and inexpensive method to implement a square-root extractor for voltage input signal. The proposed extractor is based on the use of two operational amplifiers (op amps) as only active elements. The proposed technique employs the op amp supply-current sensing to achieve an inherently quadratic characteristic. The low-output distortion in output signal can be achieved. Experimental results verifying the characteristic of the proposed circuit are also included.