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| STEVAL－IME013V1超聲波脈沖發(fā)生器評(píng)估方案 |
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| 文章來(lái)源： 更新時(shí)間：2016/4/27 14:25:00 |
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ST公司的STHV800是八路單片高壓高速脈沖發(fā)生器,集成了控制器邏輯接口電路,電平轉(zhuǎn)換器,MOSFET柵極驅(qū)動(dòng)器,噪音抑制二極管,以及大功率P溝和N溝MOSFET輸出級(jí),峰值電流大于2A,輸出電壓0到 ±90 V,工作頻率高達(dá)20MHz,主要用在醫(yī)用超聲圖像,脈沖波形發(fā)生器,NDT超聲發(fā)送器,壓電傳送設(shè)備.本文介紹了STHV800主要特性和框圖,以及基于STHV800的評(píng)估板STEVAL-IME013V1主要特性,硬件框圖,布局圖,兩種超聲波脈沖發(fā)生器解決方案框圖,以及評(píng)估板電路圖和材料清單.
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 be used in both a dedicated RX chain per channel or in a multiplexing configuration.
The clamp circuit has a current capability up to 2 A and works directly on the output pin, carrying this node exactly to zero. This feature allows minimized injection change during the transition from clamp to RX state.
In addition, the STHV800 includes self-biasing circuitry which allows very low power consumption during the RX phase (down to 200 µW global power dissipation) and thermal shutdown block sensing by an external dedicated pin (THSD).
One of the main benefits of this device is that it requires very few external components: only decoupling capacitors on the HV and LV supplies, and a resistor to pull up the THSD pin (moreover, this resistor can be shared by many devices).
Each channel is driven independently by only 2 digital bits, which in CW mode become one bit. An external clock can be used with the STHV800 to synchronize all the input signals. This feature, however, is optional: if the CK pin is tied to ground the device works in asynchronous mode.
STHV800主要特性:
High-density ultrasound transmitter
Two independent half-bridges per channel
0 to ±90 V output voltage
Power-up free
Synchronization of the input signals (selectable) by an external clock
Up to 20 MHz operating frequency
Low-power, high-voltage, high-speed drivers
2 independently-supplied half bridges (shorted-option) for each channel, one dedicated to continuous wave (CW) mode
Main half bridge: ±2 A source and sink currentDown to 20 psjitterLow 2nd harmonic distortion
CW half bridge:±0.3 A source and sink currentDown to 10 psjitterVery low power consumption
Fully integrated real clamping-to-ground function
8 Ω synchronous active clamp
±2 A source and sink current
Fully integrated TR switch
8 Ω ON resistance
Up to 300 MHz BW
Current consumption down to 10 μA in RX phase
Receiver multiplexing function
1.8 V to 3.6 V CMOS logic interface
Auxiliary integrated circuits
Noise blocking diodes
Anti-leakage on output node
Fully self-biasing architecture
Thermal protection
Latch-up free due to HV SOI technology
Very few external passive components or supplies needed
STHV800應(yīng)用:
• Medical ultrasound imaging
• Pulse waveform generator
• NDT ultrsound transmission
• Piezoelectric transducer drivers
• Point-of-care ultrasound imaging equipment
圖1.STHV800功能框圖
基于STHV800的評(píng)估板STEVAL-IME013V1
The STEVAL-IME013V1 is an evaluation board designed around the STHV800 ultrasound pulser IC, a state of the art device for ultrasound imaging applications. The system can drive eight transducers as 8-channel transmitters and display the output waveforms directly on an oscilloscope by connecting the scope probe on the relative BNCs. Four preset waveforms are available to test the HV pulser under different conditions. It is also possible to change these preset waveforms via a PC GUI
圖2.評(píng)估板STEVAL-IME013V1外形圖
評(píng)估板STEVAL-IME013V1主要特性:
Suitable for ultrasound imaging applications
8 monolithic channels, 3 level high voltage pulser
Integrated T/R switch
On-board equivalent piezoelectric load implemented through an R/C equivalent network
USB interface is available to upload customized output waveforms
Built in microcontroller Flash memory available for storing customized waveforms
High voltage screw connectors to power the STHV800
Automatic lockout overvoltage protection
7 LEDs to check EVAL BOARD status and proper operation
Human machine interface to select, start and stop the stored output waveforms
圖3.評(píng)估板STEVAL-IME013V1硬件框圖
圖4.評(píng)估板STEVAL-IME013V1布局圖
圖5.超聲波脈沖發(fā)生器解決方案1框圖
圖6.超聲波脈沖發(fā)生器解決方案2框圖
圖7.評(píng)估板STEVAL-IME013V1電路圖
評(píng)估板STEVAL-IME013V1材料清單:
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