| 摘要 |
<p>A voltage drop detector circuit (1) for detecting the drop of output voltage in a switching regulator that has an error detector circuit for detecting an error between the output voltage and a rated value, and a feedback circuit (PC1, R1) for controlling a control circuit (2) of the switching transistor depending on output signals of the error detector circuit (R2, R4, R5, IC1). The voltage drop detector circuit (1) is so constituted as to operate with the outputs of the error detector circuit (R2, R4, R5, IC1) as control inputs. When the output voltage becomes smaller than the rated value, the current of the shunt regulator (IC1) is blocked whereby the transistor (Q2) is turned off, and a drop in the output is produced from the terminals (E1, E2).</p> |
