Supply-Doubled Pulse-Shaping High Voltage Pulser for CMUT Arrays.
Supply-Doubled Pulse-Shaping High Voltage Pulser for CMUT Arrays.
复制标题
DOI：
10.1109/tcsii.2017.2691676
复制
发表时间：
2018-03
期刊：
影响因子：
--
通讯作者：
Ghovanloo M
中科院分区：
文献类型：
--
作者：
Jung G;Tekes C;Pirouz A;Degertekin FL;Ghovanloo M
提出了一种电源倍增的脉冲整形高压脉冲发生器，用于医学超声成像，特别是使用电容式微机械超声换能器(CMUT)的应用。该脉冲发生器采用自举电路与动态偏置堆叠晶体管相结合，允许在工艺极限以上进行高压操作，而不会降低器件可靠性。新的脉冲发生器克服了传统单极脉冲发生器的电源电压限制，产生的输出信号几乎是电源电平的两倍。它还可以产生三电平脉冲，以进一步优化传输压力信号。采用0.18-μm HV cmos/dMOS工艺实现了一个60V器件的概念验证样机。测试结果表明，该高压脉冲发生器在45V电源下可以安全地产生高达85Vpp的可控三能级脉冲。将脉冲器连接到中心频率为8.3 MHz、电容为2pF的CMUT上进行声学测量。对被测CMUT的脉冲形状进行了调整，以产生最大压力输出，结果与大信号CMUT模型吻合较好。
A supply-doubled pulse-shaping high voltage (HV) pulser is presented for medical ultrasound imaging applications, particularly those that use capacitive micromachined ultrasonic transducers (CMUT). The pulser employs a bootstrap circuit combined with dynamically-biased stacked transistors, which allow HV operation above process limit without lowering device reliability. The new pulser overcomes supply voltage limitation of conventional unipolar pulsers by generating output signals that are almost twice the supply level. It also can generate three-level pulses to further optimize the transmit pressure signals. A proof-of-concept prototype has been implemented in 0.18-μm HV CMOS/DMOS technology with 60 V devices. Measurement results show that the HV pulser can safely generate controllable three-level pulses with up to 85 Vpp from 45 V supply. Acoustic measurements are conducted connecting the pulser to a CMUT with 2 pF capacitance and 8.3 MHz center frequency. The pulse shape has been adjusted for the CMUT under test to generate maximum pressure output and the results are in good agreement with a large signal CMUT model.