CMOS ultrasonic analogue front-end with reconfigurable pulser/switch for medical imaging applications

A highly integrated bidirectional analogue front-end (AFE) circuit for interfacing capacitive micromachined ultrasound transducer in medical imaging systems is presented. The proposed AFE features a reconfigurable high-voltage (HV) pulser which generates over 15 V pulses at 2.6 MHz in the transmit mode and also operates as an HV isolation switch for the receive path circuits, thereby saving significant silicon area. The AFE also includes a low-power low-noise preamplifier which achieves 103 dBΩ transimpedance gain at 2.6 and 5 MHz bandwidth while operating at 1.65 V supply voltage. The AFE integrated circuit (IC) is implemented using 0.18 μm standard CMOS process and the total area of the single-channel core is 0.052 mm² which is more than 65% of size reduction in comparison to previous work.