STHV800 Ultrasound Pulser Board
Created: Jan 29, 2017
No description available.
High-frequency sound waves are non-audible to human hearing but are used in some medical applications. Ultrasound or also know as sonogram is one application which uses a frequency of 10MHz or higher to perform the scan which create images of the subject. The reference design is an evaluation board based on STHV800 ultrasound pulser. The STHV800 is an octal, monolithic, high-voltage and high-speed pulse generator. It is designed for medical ultrasound applications, but can be used for other piezoelectric, capacitive or MEMS transducers.
The low voltage side of the board is designed and powered during programming which the PC is connected with a 5VDC through USB Mini B connector to supply the STM32F4. The STM32F427 is fully dedicated to generate the bitstream on its GPIO pins to drive the pulser output channels. The MCU unit drives the pulser channels through the use of different General Purpose I/O (GPIO) pins. After the MCU is programmed, it can act now as a stand-alone device. The STHV800 integrates a controller logic interface circuit (compatible with both 1.8V and 3.3V input signals), level translators, MOSFET gate drivers, noise blocking diodes, and high power P-channel and N-channel MOSFETs as the output stage for each channel. These MOSFETs are capable of providing more than 2A of peak output current. Each channel has a dedicated bridge in order to reduce power dissipation and jitter during continuous wave mode (peak current is limited to 0.3A). The eight independent T/R switches can be used in both a dedicated RX chain per channel or in a multiplexing configuration. Also, each of the channels can be driven independently by dibits, which can become a bit if in CW mode. An external clock can be used with the STHV800 to synchronize all the input signals.
The STHV800 can also be used in some other applications like generating pulse waveform, NDT ultrasound transmission, and driving piezoelectric transducer. One advantage of STHV800 is that it requires a minimal amount of external components.