Inverter circuit

Abstract

An inverter circuit includes an IGBT ( 3 ) and an IGBT ( 4 ) connected in series between a power supply potential (Vcc) and a GND potential, and an HVIC ( 1 ) and an LVIC ( 2 ) for respectively controlling actuation of the IGBTs ( 3 ) and ( 4 ). The inverter circuit also includes a capacitor ( 5 ), a diode ( 6 ), and a resistor ( 7 ). The capacitor ( 5 ) is connected between a terminal (VS) and the GND potential. The diode ( 6 ) has a series connection to the capacitor ( 5 ) between the terminal (VS) and the GND potential, with such a polarity that a forward current flows from the GND potential to the terminal (VS). The resistor ( 7 ) is connected in parallel to the capacitor ( 5 ).

1 . An inverter circuit, comprising: 
 a high-voltage switching element and a low-voltage switching element connected in series between a power supply potential and a GND potential;    a high-voltage drive circuit having a terminal connected to a current emission terminal of said high-voltage switching element while supplying a reference potential of a high-potential inner circuit, said terminal of said high-voltage drive circuit being referred to as a terminal VS;    a capacitor connected between said terminal VS and said GND potential;    a diode having a series connection to said capacitor between said terminal VS and said GND potential, with such a polarity that a forward current flows from said GND potential to said terminal VS; and    a resistor connected in parallel either to said diode or to said capacitor, or both.    
   
   
       2 . An inverter circuit, comprising: 
 a high-voltage switching element and a low-voltage switching element connected in series between a power supply potential and a GND potential;    a high-voltage drive circuit having a terminal connected to said GND potential while supplying a reference potential of a low-potential inner circuit, said terminal being referred to as a terminal COM; and    a diode connected between said terminal COM and said GND potential, with such a polarity that a forward current flows from said terminal COM to said GND potential.    
   
   
       3 . The inverter circuit according to  claim 2 , 
 wherein said diode is a fast recovery diode.    
   
   
       4 . The inverter circuit according to  claim 2 , 
 wherein said high-voltage drive circuit includes a plurality of high-voltage drive circuits,    wherein said plurality of high-voltage drive circuits are provided in respective phases of said inverter circuit,    wherein said terminals COM of said plurality of high-voltage drive circuits are connected to each other, and    wherein said diode is a common diode among said plurality of high-voltage drive circuits.    
   
   
       5 . The inverter circuit according to  claim 2 , 
 wherein said high-voltage drive circuit further has a terminal for receiving power to drive said low-potential inner circuit, said terminal for receiving said power being referred to as a terminal Vcc,    said inverter circuit further comprising a Zener diode having an anode connected to said terminal COM, and a cathode connected to said terminal Vcc.    
   
   
       6 . The inverter circuit according to  claim 5 , 
 wherein said high-voltage drive circuit includes a plurality of high-voltage drive circuits,    wherein said plurality of high-voltage drive circuits are provided in respective phases of said inverter circuit,    wherein said terminals COM of said plurality of high-voltage drive circuits are connected to each other, and    wherein said diode and said Zener diode are each a common diode among said plurality of high-voltage drive circuits.    
   
   
       7 . The inverter circuit according to  claim 2 , 
 wherein said diode is a Zener diode.    
   
   
       8 . The inverter circuit according to  claim 7 , 
 wherein said high-voltage drive circuit includes a plurality of high-voltage drive circuits,    wherein said plurality of high-voltage drive circuits are provided in respective phases of said inverter circuit,    wherein said terminals COM of said plurality of high-voltage drive circuits are connected to each other, and    wherein said Zener diode is a common diode among said plurality of high-voltage drive circuits.    
   
   
       9 . An inverter circuit, comprising: 
 a high-voltage switching element and a low-voltage switching element connected in series between a power supply potential and a GND potential;    a high-voltage drive circuit having a terminal connected through a bootstrap power supply capacitor to a current emission terminal of said high-voltage switching element, said terminal of said high-voltage drive circuit being referred to as a terminal VDB; and    a diode having a series connection to said bootstrap power supply capacitor between said current emission terminal and said terminal VDB, with such a polarity that a forward current flows from said current emission terminal to said terminal VDB.