A 15-V Bidirectional Ultrasound Interface Analog Front-End IC for Medical Imaging Using Standard CMOS Technology

A high-voltage (HV) interface analog front-end (AFE) integrated circuit (IC) for medical ultrasound imaging applications using 0.18-μm standard CMOS process is presented. The proposed AFE IC includes a HV pulser in the transmit path that safely generates up to 15-Vpp of unipolar pulses at 2.6 MHz, a HV switch for isolation between transmitter and receiver frontend parts, and a 95.1-dBΩ low-power transimpedance preamplifier with 12-MHz bandwidth and 3.5-pA/√Hz input referred noise in the receive path operating at a low 1.1-V supply voltage. Both the pulser and the switch utilize dynamically-gate-biased stacked 3.3-V transistors to enable HV operation without compromising device reliability. The implemented single-channel AFE IC prototype intended for interfacing capacitive micromachined ultrasound transducer consumes 0.15 mm2 of core die area, making it feasible to be applied for various multi-array medical ultrasound imaging systems.