This thesis discusses the architecture, circuit implementation and the simulation results of a cable driver for ultrasound imaging. This design is capable of providing higher bandwidth, better dynamic range, wider output swing, and ideal biasing voltage at the output terminal.
The driver design starts from the analysis and simulation of the prior design. After quantifying the performances of the previous driver, a solid starting point is made. The advantages and disadvantages of the prior topology are discussed in detail. In order to further optimize the performances without significantly increasing the power consumption level, a new circuit topology is proposed and analyzed.
Class AB operation is proposed to improve the power efficiency. Floating gate technique is implemented to provide Class AB operation. The new design is a two stage OpAmp with a negative feedback loop, which means the stability of the circuit needs to be guaranteed.
The cable driver is implemented in TSMC 180 nm technology. The simulation result shows the new topology is able to drive the capacitive load of 100pF, and the with a strict current budget of 330µA.
Keywords: Ultrasound imaging, cable driver, buffer, phase margin, slew rate, power consumption