POWER SWITCHING CELL WITH NORMALLY CONDUCTING FIELD-EFFECT TRANSISTORS

摘要

A power switching cell with normally conducting field-effect transistors with non-insulated control comprises at input a current switch Τ1 receiving the command input signal VIN of the cell on an activation input g1, and at output, a power transistor T2 for switching a high voltage VDD applied to its drain d2, onto its source s2 linked to the output port Out of the cell. The control of the gate g2 of the power transistor T2, whose source s2 is floating, as a function of the input signal VIN, is ensured by an auto-bias circuit P connected between its gate g2 and its source s2. The current switch is connected between the auto-bias circuit P and a zero or negative voltage reference. The auto-bias circuit comprises a transistor T3 whose source s3, or drain d3, as appropriate, is connected to the gate, or to the source s3, as appropriate, of the power transistor. The gate g3 of this transistor T3 is itself biased by an auto-bias resistor R3 connected between its gate g3 and its source s3, and in series between the current switch Τ1 and the source s3. The transistors are advantageously HEMT-type transistors using AsGa or GaN technology.