ST STHV800超声波图像系统解决方案

ST公司的STHV800是大容量超声波发送器,每路有两个独立的半桥,输出电压0- ±90 V,输出电流±2 A,由外部时钟可同步输入信号,工作频率高达20MHz,主要用在医用超声波图像,脉冲波形发生器,NDT超声波发送,压电变送器驱动等.本文介绍了超声波系统框图,STHV800主要特性,内部框图,评估板STEVAL-IME009V1主要特性,硬件框图,电路图和材料清单.
Remarkable advances are taking place in medical imaging. Ultrasound imaging helps examine anatomical activity within patients. ST provides with a very wide portfolio of products from discretes to 32 bit digital processors and memories that help to further enhance imaging within ultrasound imaging equipments. The block diagram facilitates your selection among a wide selection of recommended applicable products.

图1.超声波系统框图
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 device integrates a controller logic interface circuit (compatible with both 1.8 V and 3.3 V 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 2 A 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 0.3 A). This CW bridge has dedicated power supplies (HV_CW) which are fully independent on the main HV supplies.
These HV_CW supplies can be shorted to the HV supplies. The fundamental structure of each channel also consists of active clamping to ground circuitry, anti-leakage and anti-memory block, a thermal sensor to protect the device and an integrated TR-switch (just 8 Ω as equivalent resistor ) to connect the HV output to its LV output, guaranteeing strong decoupling during the transmission phase.
The eight independent T/R switches can b...