| 摘要 |
<P>PROBLEM TO BE SOLVED: To shorten a turnoff time while suppressing noise even if a threshold voltage of an output transistor fluctuates in a small circuit scale. <P>SOLUTION: When a driving signal Sd is L, a transistor T1 is turned on and a transistor T2 is turned off to bring VGS(T3) substantially equal to a supply voltage Vcc, which turns on a transistor T3. When the driving signal Sd becomes H, the transistor T1 is turned off and the transistor T2 is turned on. A transistor T4 is then turned on to bypass a resistance R2, so that a gate charge of the transistor T3 discharges quickly via the transistors T4, T2. When the VGS(T3) falls below Vth(T4)+VDS(T2), the transistor T4 is turned off, so that the gate charge of the transistor T3 discharges gradually via the resistance R2 and the transistor T2. Since threshold voltages of the transistors T3, T4 tend to be the same, the VGS(T3) can fall to VTH(T3) to turn off the transistor T4. <P>COPYRIGHT: (C)2012,JPO&INPIT |
