34.1 An 8960-Element Ultrasound-on-Chip for Point-of-Care Ultrasound

Integrated Transceivers for Emerging Medical Ultrasound Imaging Devices: A Review

“…For instance, the ASIC can provide full digitization (Fig. 4b) and further processing of the echo signals [8], [20]. In the case of portable ultrasound probes, this is an essential step, as the imaging system with analog front-ends and ADCs has been replaced by a smartphone or tablet [1].…”

“…This requires an extra level-translator to drive the high-side PMOS relative to the HV supply (HVDD). It can be implemented using either a low-power capacitively-coupled latch, similar to [28], or a pull-up resistor in parallel with voltage-clamping diodes [8], [26]. Adding extra digital buffers between the level-translators and the gates of HV transistors helps to speed up switching [26], but requires a floating ground at the voltage of HVDD-V GS , where V GS is the gate-source voltage of the HV transistor.…”

“…7b. The typical implementation of a bipolar pulser uses either an HV inverter [8] or a source-follower-based push-pull stage [7] with positive and negative HV supplies as the front-end stage.…”

“…This creates room for designers to trade the capability of dynamic energy saving for a more compact multi-level pulser. Sanchez et al proposed a feedback-based 7-level pulser small enough to be closely integrated with a 208μm-pitch CMUT array [8]. Fig.…”

“…Moreover, in terms of channel count, these architectures are not scalable to 3D imaging. Integrated transceiver circuits, closely integrated with the ultrasound transducer array, can solve these problems, e.g., [2], [7], [8]. Combined with the move from conventional labour-intensive and expensive bulk-piezoelectric transducer technology to micro-machined transducers, integrated circuits also pave the way to the cost reduction needed for more widespread use [1].…”