Patent ID: 6388287
Filing Date: 2002-05-14
Classification: H01L,H03K

Abstract:
A switch mode power supply, comprising:a switching transistor having a load path formed by a first main connection and a second main connection, said first main connection and said second main connection for receiving a voltage applied thereto, said switching transistor including a semiconductor body with a semiconductor layer of a first conductance type forming a drift area; a load connected in series with said load path of said switching transistor; a continuous drain region of a second conductance type incorporated into said drift area and connected to said first main connection; a continuous source region of the second conductance type incorporated into said drift area and connected to said second main connection; a reverse-biased pn-junction produced by an interaction between said semiconductor body and said continuous drain region and between said semiconductor body and said continuous source region; said reverse-biased pn-junction having a large inner voltage-dependent surface area that is variable as a function of the voltage applied to said first main connection and said second main connection; when the voltage applied is 10 V, said switching transistor is characterized by a first product of a switch-on resistance Ron and a gate charge Qgtot, the first product given by: Ron*Qgtot/10 V&lE;2.5 ns; and when the voltage applied is 400 V, said switching transistor is characterized by a second product of the switch-on resistance Ron and energy Eds stored in a drain-source capacitance, the second product given by Ron*Eds&lE;1.6 V2 &mgr;s.