| 摘要 |
PROBLEM TO BE SOLVED: To provide a current limit circuit capable of setting a current limit value (short circuit current value) in time of output grounding to be small with a comparatively simple circuit, and freely setting a load characteristic of an output voltage thereof. SOLUTION: When a drain current of a power transistor Qa of a voltage control circuit A becomes large, a drain current I2 of a mirror transistor Qb of a current limit circuit B and a current I3 flowing through a transistor Q3 of a current mirror circuit also become large. Because an output current I4 of a V/I conversion circuit C changes in proportion to the output voltage Vout, the current limit value Ilim satisfies Ilim=n×äVBE/Rm+Vout×R2/Rn×(R1+R2)}. Accordingly, because a maximum limit current has a value according to the output voltage of a regulator, a current limit characteristic can be set to be a chevron-shaped characteristic. COPYRIGHT: (C)2006,JPO&NCIPI
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