500V three-phase inve r t e r ICs for DC brushless motor dr ives has been developed, for t h e first t i m e , using a new d ie l ec t r i c isolat ion method based on s i l icon w a f e r direct-bonding(D1SDB). The new D I method has an advantage t h a t it is completely compatible with conventional junction i so l a t ion and Resurf principle. been developed without using c a r r i e r lifetime con t ro l process. Thus, t h e developed I C s can be fabricated using only conventional LSI processes. operate at 16kHz PWM frequency, and realize compact low noise DC brushless motors when ins t a l l ed inside t h e motor. function is also proposed. 600V high speed lateral IGBTs has The developed 500V i nve r t e r I C s A new shor t c i r cu i t protect ion