Low voltage isolation switch, in particular for a transmission channel for ultrasound applications

摘要

A low voltage isolation circuit is coupled between an input terminal for receiving a high voltage signal and an output terminal for transmitting the high voltage signal to a load. The isolation circuit includes a driving block; having a first driving transistor coupled between a first voltage reference and an intermediate node and a second driving transistor coupled between the intermediate node and a second voltage reference; an isolation block connected between the input and output terminals and, through a protection block to the intermediate node. The protection block includes first and second protection transistors (MD1, coupled in anti-series to each other and having control terminals receiving complementary protection driving signals. The isolation block includes a voltage limiter block, a diode block and a control transistor connected across the diode block between the input and output terminals and having a control terminal connected to the intermediate node through the protection block.

主权项

1. A low voltage isolation switch, comprising
an input terminal configured to receive a high voltage signal; an output terminal configured to transmit said high voltage signal to a load; first and second voltage reference terminals configured to receive first and second voltage references, respectively; a driving block electrically coupled between the first and second voltage reference terminals and including:
a first driving transistor electrically coupled between said first voltage reference terminal and an intermediate node; anda second driving transistor electrically coupled between said intermediate node and said second supply voltage reference terminal; a protection block; an isolation block electrically coupled between the protection block and the output terminal and electrically coupled by the protection block to the intermediate node, the isolation block including:
a diode block electrically coupled between said input and output terminals;a control transistor electrically coupled across said diode block and having a control terminal electrically coupled to said intermediate node by said protection block; anda voltage limiter block coupled between the input terminal and the control terminal of the control transistor.