The HV748DB1 is used to generate the basic high voltage pulse waveform as an ultrasound transmitting pulser. The HV748 circuit uses the DC coupling method in all level translators. There are no external coupling capacitors needed. The VPP and VNN rail voltages can be changed rather quickly, compared to a high voltage capacitor gate coupled driving pulser. This direct coupling topology of the gate drivers not only saves two high voltage capacitors per channel, but also makes the PCB layout easier.