| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a semiconductor circuit which is formed in a MOS integrated circuit and which has a rectifier function that is practicable by electrically setting a well to be a floating state. SOLUTION: Since an N-well layer 20a being a base is electrically in the floating state in a parasitic bipolar transistor shown in broken lines, a route where current flows from a P-type diffusion layer 30b to the Nwel layer 20a is not formed. Thus, the parasitic bipolar transistor does not become an ON state. Since the N-well layers 20a and 20b are similarly in the floating state in the other parasitic bipolar transistor constituted by the P-type diffusion layer, the N-well layer and the P-type substrate, any parasitic bipolar transistor does not become the ON state and the operation of a half-wave rectifier circuit by first and second transistors Tr1 and Tr2 cannot be prevented. Consequently, the semiconductor circuit which does not have malfunctions owing to the parasitic transistor and which has the rectifier function can be mounted on the MOS integrated circuit.</p> |
