Transmit circuit for imaging with ultrasound

摘要

A digital-to-analog converter with differential outputs is connected to two difference amplifiers through current splitters. The current splitters isolate the compliance voltage of the digital-to-analog converter so that larger resistances may be used with the difference amplifiers. The larger resistances allow for better signal-to-noise ratio performance of the transmit circuit. The difference amplifiers provide current signals to a push-pull output amplifier through their supply nodes. A single scaling resistor connects between the conventional outputs of two differential amplifiers to reduce mismatching between the positive and negative waveform paths. As a result of the feedback between the two difference amplifiers, a lower level of subharmonic and/or harmonic distortion products is achieved.