| 摘要 |
PURPOSE:To achieve high speed operation, by increasing the threshold voltage of an insulation gate type field effect transistor (MOST) of an input stage than that of transistors of an internal circuit in the same chip. CONSTITUTION:The channel length of an MOST11 at an input stage is made longer than that of other MOSTs to obtain higher threshold voltage than that of other MOST2 and MOST3. When an external control signal In moves from high to low level of TTL at t1, even if this low level is lower than the threshold voltage of the MOST3 of the internal circuit, since the channel length of an MOS T11 is made longer so that the low level is lower than the threshold voltage of the MOST11 at the input stage, the MOST11 is nonconductive, the potential at a node A is charged through the MOST2 at a conductive state and increases to the level of (power supply voltage - threshold voltage of MOST2). Thus, the activation of an internal circuit 10 receiving the output of the node A can be made without delay. |
