| 摘要 |
PROBLEM TO BE SOLVED: To obtain a switch circuit which makes no excessive current to flow to a substrate, suppresses the generation of switching noise, and has a stable output potential by deactivating a parasitic PNP transistor formed at an output PNP transistor of an analog switch circuit. SOLUTION: This switch circuit is equipped with a current feedback means which compares the collector potential of the output PNP transistor Q4 with the base potential to output a control current Icont1 when the collector potential is higher and feeds the Icont1 back to the emitter of an input transistor Q1 to vary the base potential of the output PNP transistor Q4 to a level above the collector potential, and the parasitic PNP transistor formed at the output PNP transistor Q4 is deactivated by eliminating the potential differenceΔV between the collector potential and the base potential of the output PNP transistor Q4 by the current feedback means, thereby eliminating the generation of switching noise.
|
