| 摘要 |
PROBLEM TO BE SOLVED: To provide an overcurrent detector capable of quickly operating an overcurrent detecting function when a transient period is completed by setting an appropriate mask time to the transient period even if the transient period of FET (T1) changes. SOLUTION: The detector comprises a comparator (CMP1) which compares a measured voltage V5 with a reference voltage V4 and outputs an overcurrent determination signal when the measured voltage V5 exceeds the reference voltage V4, a saturation determination circuit which detects the fact that a differential value (VG-V1) between a control voltage (VG) of FET (T1) and a voltage (V1) applied to the positive side of the FET(T1) exceeds a specified voltage (δ) which is higher than a threshold voltage (Vth1), and an AND circuit (AND1) which performs switching operation so that the overcurrent determination signal can be outputted to a driver circuit when the saturation determination circuit determines that the differential value (VG-V1) has exceeded the specified voltage (δ). COPYRIGHT: (C)2006,JPO&NCIPI
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