ST STEVAL－IME003V1医疗超声波图像解决方案

发布时间：2012-9-5 11:09 发布者：1770309616

ST公司的STEVAL-IME003V1是基于四路STHV748高压脉冲发生器的超声波图像演示板,输出波形通过连接示波器探针到BNC就能直接在示波器上显示.16种预置波形能用来在变化的条块下测试高压(HV)脉冲发生器.而STHV748是±90 V 2 A高速脉冲发生器,工作频率高达20MHz,主要用于医疗超声图像,脉冲发生器,NDT超声发送和压电传感器驱动器.本文介绍了STHV748主要特性,典型应用电路以及STEVAL-IME003V1主要特性,框图,电路图,材料清单和PCB元件布局图.

The STEVAL-IME003V1 demonstration board is designed around the STHV748 4-channel high voltage pulser, a state-of-the-art device designed for ultrasound imaging applications.

The output waveforms can be displayed directly on an oscilloscope by connecting the scope probe to the relative BNCs. 16 preset waveforms are available to test the HV pulser under varying conditions.

STHV748 is 5-level, ±90 V, 2 A high speed pulser with four independent channels.This monolithic, high-voltage, high-speed pulser generator features four independent channels. It is designed for medical ultrasound imaging applications, but it can also be used for driving other piezoelectric, capacitive or MEMS based transducers. The STHV748 comprises a controller logic interface circuit, level translators, MOSFET gate drivers, noise blocking diodes, and high-power P-channel and N-channel MOSFETs as the output stage for each channel, clamping-to-ground circuitry, anti-leakage, anti-memory effect block, thermal sensor, and a T/R switch which guarantees an effective decoupling during the transmission phase. Moreover, the STHV748 includes self-biasing and thermal shutdown blocks. Each channel can support up to five active output levels with two half bridges. The output stage of each channel is able to provide ±2 A peak output current. In order to reduce power dissipation during continuous wave mode, a dedicated half bridge is available and the peak current is limited to 0.6 A.

STHV748主要特性:

0 to ±90 V output voltage

Up to 20 MHz operating frequency

Embedded low-power, floating high-voltage drivers (external voltage rails can be also used)

Mode operations:

3/5-levels output waveform

±2 A source and sink current

Down ≤ 20 ps jitter

Anti-cross conduction function

Low 2nd harmonic distortion

Fully integrated clamping-to-ground function

8 Ω synchronous active clamp

Anti-leakage on output node

Dedicated half bridge for continuous wave (CW) operations

≤ 0.1 W power consumption

±0.6 A source and sink current

≤ 10 ps jitter

Fully integrated T/R switch

13.5 Ω on resistance

HV MOS topology to minimize current consumption

Up to 300 MHz BW

Receiver multiplexing function

2.4 V to 3.6 V CMOS logic interface

Auxiliary integrated circuits

Noise blocking diodes

Fully self-biasing architecture

Anti-memory effect for all internal HV nodes

Thermal protection

Standby function

Latch-up free due to HV SOI technology

Very few external passive components needed

STHV748应用:

■ Medical ultrasound imaging

■ Pulse waveform generator

■ NDT ultrasound transmission

■ Piezoelectric transducers driver

图1.STHV748典型应用电路

图2.STEVAL-IME003V1超声波图像演示板外形图

STEVAL-IME003V1主要特性:

● Based on the STHV748 device for ultrasound imagine applications

● 4 monolithic channels, 5 level high voltage pulser

● Integrated T/R switch

● On-board equivalent piezoelectric load implemented by means of:

– R/C equivalent network

– SMD landing areas available for a customized output load

● USB interface available to upload customized output waveforms

● 4 Mb serial Flash memory available for storing customized waveforms

● Memory expansion connector is available to expand serial Flash size

● High voltage and low voltage connectors to power the STHV748

● 25 LEDs to check the board status and proper operation

● Human machine interface to select, start and stop the stored output waveforms