| 摘要 |
PROBLEM TO BE SOLVED: To provide a high precision overcurrent detection circuit in which detection error resulting from early effect is eliminated and temperature dependency of detection error is suppressed while sustaining high power efficiency of the entire circuit. SOLUTION: The overcurrent detection circuit 14 for detecting overcurrent state of a power MOS transistor 2 delivering a current from the drain electrode to a load 6 and outputting an overcurrent detection signal comprises a detection MOS transistor 3 having a source electrode and a gate electrode connected, respectively, with the source electrode and gate electrode of the power MOS transistor 2, a constant current circuit 4 connected with the drain electrode of the detection MOS transistor 3 and supplying a predetermined constant current Ic thereto, and a comparator 5 for outputting the overcurrent detection signal based on comparison results of the potentials at the drain electrode of the power MOS transistor 2 and at the drain electrode of the detection MOS transistor 3. COPYRIGHT: (C)2006,JPO&NCIPI
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