LOW VOLTAGE ISOLATION SWITCH, IN PARTICULAR FOR A TRANSMISSION CHANNEL FOR ULTRASOUND APPLICATIONS

摘要

A low voltage isolation circuit (1) is described inserted between a connection node (HVout) to a matrix (2) of switches suitable for receiving a high voltage signal (IM) and a connection terminal (pzt) to a load (PZ) suitable for transmitting said high voltage signal (IM) to said load (PZ) of the type comprising at least one driving block (5) inserted between a first and a second voltage reference (Vss, - Vss) and comprising at least a first driving transistor (M l), inserted, in series with a first driving diode (Dl), between the first voltage reference (Vss) and a first driving central circuit node (Xc) and a second driving transistor (M2), in turn inserted, in series with a second diode (D2), between the driving central circuit node (Xc) and the second supply voltage reference (-Vss). The switch comprises an isolation block (8) connected to the connection terminal (pzt), to the connection node (HVout) and to the driving central circuit node (Xc) and comprising at least one voltage limiter block (6), a diode block (7) and a control transistor (MD), in turn connected across the diode block (7) between the connection node (HVout) to the matrix (2) of switches and the connection terminal (pzt) to the load (PZ) of the low voltage isolation switch (1) and having a control terminal (XD) connected to the driving central circuit node (Xc).