A programmable analog delay line for Micro-beamforming in a transesophageal ultrasound probe

Abstract

Our research project is to design a readout IC for an ultrasonic transducer consisting of a matrix of more than 2000 elements. The IC and the matrix transducer will be put into the tip of a transesophageal probe for 3D echocardiography. A key building block of the readout IC, a programmable analog delay line, is presented in this paper. It is based on the time-interleaved sample-and-hold (S/H) principle. Compared with conventional analog delay lines, this design is simple, accurate and flexible. A prototype has been fabricated in a standard 0.35μm CMOS technology. Measurement results showing its functionality are presented.