| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable the use of a low withstand pressure transistor for switching element by forming a switching element of a pair of transistors of an input terminal side transistor and an output terminal side transistor connected in series to each other. SOLUTION: When a PMOS transistor PM1 is turned off and a NMOS transistor NM2 is turned on, voltage at 15 V as the maximum is applied to both ends of a pair of transistors. But, since the PMOS transistor PM1 is turned off, current is not flowed, and source voltage of the PMOS transistor PM21 becomes a voltage obtained by subtracting a threshold value voltage from a gate voltage, and the source voltage of the PMOS transistor PM21 is equal to the gate voltage (0 voltage) and the withstand pressure between a source and a drain at about 15 V is unnecessary for the PMOS transistor PM1, and a low withstand pressure transistor PMOS at about 10 V can be used. Chip size of a semi-conductor chip to be loaded on a switching circuit can be reduced.</p> |
