| 摘要 |
<p>PURPOSE:To limit overcurrent of a load circuit by inserting a bipolar transistor constituting a current path between the gate and drain of a MOSFET for output and inserting a resistor between a base thereof and a source of the MOSFET for output. CONSTITUTION:Bipolar transistors 7a, 7b are inserted between, a gate and a drain of the MOSFET 3a and 3b for output so as to constitute a current path for limiting a load current, and the resistors 8a, 8b are inserted between the base thereof and a base of the MOSFET 3a, 3b. Accordingly, when a potential difference to be generated between the source and the drain of the MOSFET 3a, 3b reaches prescribed voltage, the transistors 7a and 7b are made conductive to lower potential between the gate and the source of the MOSFET 3a and 3b and to change the MOSFET 3a, 3b to be high impedance so as to be able to limit the load current within a prescribed value and to be able to relatively free set an upper limit value of the load current thus to add a limiting function of the load current without increasing a manufacturing process and a chip area.</p> |
