High voltage switching circuit (1) with: - an input port (IN) that has a positive terminal (IN +) and a negative terminal (IN-), which are electrically connected to a current generating circuit (500), so that said input port receives a predefined input current (IIN)； - an output port (OI), which has a positive terminal (OI +) and a negative terminal (OI-)； - a first output (Y1) having a positive terminal (Y1 +) and a negative terminal (Y1 -), which are electrically connected to the terminals of said output port； - a first switch (T1) and a second switch (T2) that function as current switches and are complementary field effect transistors, said first switch having a source terminal electrically connected to the positive (IN +) terminal of said port of input (IN) and a drain terminal electrically connected to the positive terminal (Y1 +) of the first output (Y1), said second switch having a source terminal electrically connected to the negative terminal (IN-) of said input port (IN ) and a drain terminal electrically connected to the negative terminal (Y1 -) of said first outlet (Y1)； characterized in that it comprises a buffer stage (BUF) that is electrically connected to the positive and negative terminals (IN +, IN-) of said input port and that has a buffer output (BF) provided with a positive terminal (BF +) and a negative terminal (BF-), said buffer stage comprising: - first and second detection circuits (B1, B2) configured to detect the voltages of the positive and negative terminals (IN +, IN-) of said input port, respectively； - first and second follower circuits (F1, F2) configured respectively to provide voltages at the positive and negative terminals (BF +, BF-) of said buffer output (BF), which follow the voltages detected by said first and second detection circuit at the positive and negative terminals (IN +, IN-) of said input port, respectively； - a first control terminal (K1) to provide a first control signal (C1)； - a first voltage level converter (A1
