| 摘要 |
PURPOSE:To attain excellent limit characteristics against ambient temperature change and to prevent the deterioration in the rate of utilization of a power supply voltage, by limiting a bias of an input of a transistor (TR) connected in series with a load to the power supply by means of a comparison means. CONSTITUTION:TRs 2 and 8 are formed on an IC chip and the emitter area of the TR2 is 100 times that of the TR8. When IM>100I0 is established where IM is a current flowing to a DC motor 3 which is load and I0 is an output current of a constant current source 9, the potential of an inverting input 10a of a comparator 10 is higher than the potential of a non-inverting input 10b and a current supplied from a bias supply means 7 is absorbed in an output 10c, then the emitter current of the TR2 rapidly decreases. Since balancing is kept when the IM is equal to 100I0, the IM is made dependent on the I0. |
