| 摘要 |
PURPOSE:To reduce the occupation area with addition of a resister and a MOSFET to the 2-phase drive circuit. CONSTITUTION:A series resister R is inserted between a drain d1 and a capacitor C2 of a MOSFET Q1 and a MOSFET Q5 is connected to a gate g3 of a MOSFET Q3. When the voltage of the input terminal I is H, the MOSFET Q1 and Q4 turns on immediately, the incoming current (a) of the capacitor load rises very sharply. Here, the MOSFET Q5 is for the gate grounding of the MOSFET Q3. The moment the input voltage turns to L, FETS Q1, Q4 and Q5 are turned off so that the falling current (b) changes slowly. In this case, if a sufficiently large resister R is selected, the value of the capacitor C2 can be reduced noticeably as the charge time constant of the capacitor C2 is tau C2R. With a less occupation capacity, the circuit can be miniaturized, thus advantageous in the placement on the same substrate with the CCD in the form of a chip. |
