Pulser and Transducer Driver for Ultrasonic Imaging Systems

• Main Authors: Feng, Shao Lin, 馮紹霖
• Other Authors: Lu, Chih-Wen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/08894732044223359413

碩士 === 國立清華大學 === 工程與系統科學系 === 103 === This thesis proposes to use current type DAC to replace the traditional unipolar and bipolar pulse generator. Using digital signal to control pulse generator can be effectively used in ultrasound scanning with variety mode, Using 200Mhz sampling frequency to control double 6-bit DAC with 128 current cell current type output with 100 ohm loading resistor to generates sine wave signal with 10MHz frequency and 40V pick voltage. Compared to conventional pulse generator , current type DAC have provide more diverse selection , make it easier to change signal amplitude and frequency, eliminating the adder and multiplier to make the system more compact , the characteristics of this work is that replaces the traditional logic circuit switch with current type logic gates MCML (Mos Current Mode Logic) using to enhance the reaction speed of the decoder that let the second harmonic distortion of the output sine wave can be pull to 39.9dbc, and reduce the process variation of current source by using staggered layout techniques .