| 摘要 |
PROBLEM TO BE SOLVED: To provide a step-up and step-down chopper type DC/DC converter circuit capable of preventing erroneous operation at stepping up or stepping down, obtaining stable operation by preventing excessive internal current, and meeting input voltage of wide range with one coil. SOLUTION: The circuit involves a step-down switching element 2 which is made unnecessary at step-up operation, and FET10, 11 for bypass formed in parallel to a serial diode 4 made unnecessary at step-down operation, and output voltage is divided through a voltage dividing resistor 16 and fed back to a step-down controller 9, thereby forming a potential difference in the output voltage at the output voltages at stepping up and stepping down within allowable output voltage precision at the time stepping up and stepping down. |
