TIDUFA5 December 2024
This design implements a full-power tree design that includes a single-stage transformerless high-voltage generation for transmit and the point-of-load low voltage for the AFEs and FPGA from a 5V USB Type-C input. The entire implementation is divided into two sections, the high-voltage power supply (see the Designing Bipolar High Voltage SEPIC Supply for Ultrasound Smart Probe application note) and a low-voltage supply. The system takes the input from a mobile phone, notebook, or desktop from a 5V USB Type-C connection. This 5V input is then used by different power management designs to power both the FPGA and the AFEs and transmitter to monitor the power consumption of various subsystems in the design. In the low-voltage supplies for both receiver and transmitter, each DC/DC converter is followed by an LDO to remove noise with a higher power supply rejection ratio (PSRR). Since the ultrasound smart probe is a noise-sensitive design, the high PSRR is a key specification for an increase in image quality. The FPGA, USB controller, and clocking supply are powered by highly efficient and low-power designs using the TPS54218, TPS7A96, and TPS74401 devices. Finally, INA231 devices are used to monitor the current of each power stage to provide a higher performing operation. Figure 2-3 shows the system block diagram.