High-voltage multi-level shifter for ultrasound applications and transmit/receive channel for ultrasound applications using said level shifter

Abstract

A multi-level shifter includes a first branch having first and second transistors coupled between a higher voltage terminal and a lower voltage terminal. The multi-level shifter comprises a second branch, in parallel with the first branch, having: a third transistor, coupled between said higher voltage reference terminal and an output node, a fourth switching transistor coupled between said output node and said lower voltage terminal. Said third and fourth transistors have respective control terminals controlled by drain terminals of said first and second transistors, respectively. The shifter includes a bidirectional battery coupled between said drain terminals of said first and second transistors to supply first and second voltages having the same magnitude and different polarities. Said fourth transistor is controlled according to the first voltage when said first transistor is turned on and said third transistor is controlled according to the second voltage when said second transistor is turned on.