| 摘要 |
PROBLEM TO BE SOLVED: To realize fuseless protection of a load circuit against overcurrent. SOLUTION: An intelligent power device IPD 10 having a temperature- sensitive protective function is employed as a semiconductor element for driving a load 2 and the sensing temperature thereof is set depending on the allowable load current. More specifically, a relationship TSD=I<2>×RON×RTEMP+TROOM is set, where RON is the ON-state resistance of a power MOSFET 11, TROOM is the ambient temperature of the IPD 10, RTEMP is the thermal resistance of the entire heat discharge system of the IPD 10, I is an allowable current level, and TSD is the sensing temperature. Since a sensing temperature is set depending on the allowable load current, the IPD 10 stops load current supply at a sensing temperature when the load current reaches an allowable level thus protecting a load circuit against overcurrent. |
