摘要 |
An overcurrent protection circuit and DC power supply that are subtly affected by process and device differences, have small input and output voltage drops, and set maximum and short-circuit current values. In a normal operation mode, a first operational amplifier and an output transistor keep the output voltage constant. In a current limiting mode, when a large current is input to an input terminal due to transient response, a second detection transistor and a third operational amplifier control a second control transistor to keep the maximum current of the output transistor constant. When voltage decreases during a foldback mode, a first detection transistor and a second operational amplifier control a first control transistor to control short-circuit current of the output transistor. A second operational amplifier decreases output current in accordance with the output voltage with a current source that maintains constant mutual conductance.
|