| 摘要 |
PURPOSE:To obtain a hysteresis having a sufficient width even when the supply voltage is low, by using an enhancement type MOS transistor which is made to operate as a ratio circuit when input signals change from a high level to a low level by earthing its source. CONSTITUTION:The titled circuit operates as ratio circuit for a depletion type MOS transistor MD1 and enhancement type MOS transistors ME2-ME4 when input signals Vi2 change from a low level to a high level, and operates as ratio circuit for the depletion type MOS transistor MD1 and enhancement type MOS transistors ME2, ME3, and ME5 when the input signals change from the high level to the low level. The source of the transistor ME5 is used with its source being earthed and the threshold when the input signals change from the high level to the low level is hardly affected by the supply voltage. Therefore, a hysteresis characteristic with a sufficient width can be obtained even when the supply voltage is low and noises carried by the input signals can be reduced. |
