| 摘要 |
PURPOSE:To obtain N (N>=3) times voltage by setting the frequency for driving the unit block of double booster circuit for producing lower stepup output to higher than that of the unit block of double booster circuit of next stage of higher stepup output. CONSTITUTION:MOSFET2 and MOSFET3 are respectively ON and OFF states according to the outputs of the output terminals Q1, Q2 of shift registers 12, 13 based on a signal CL from a terminal 11 and the inversion of an inversion signal CL from a point A at the time t1, and a point B is charged to a power voltage VSS1. The FET2 and the FET3 respectively become OFF and OFF at time t2. When these states are repeated, a point C is charged to 2VSS1. Then, an MOSFET4 and an MOSFET5 are respectively ON and OFF with a signal CL2 of the frequency of 1/2 of the signal CL at time t1+t2. Then, the FET4 and the FET5 respectively become OFF and ON at time t3. Thus, a point E will be charged to 3VSS1 soon. |
