| 摘要 |
PURPOSE:To attain the amplification to a MOS level from a TTL level by using a control voltage generating circuit comprising the series connection of MOS transistors (TRs) so as to control the fluctuation of a logic threshold value of a CMOS inverter. CONSTITUTION:If a pMOS TR is deteriorated due to the cosmic ray, its threshold voltage VTHP is increased and the current gain is reduced. That is, a pMOS TRT9 of a control voltage generating circuit is fluctuated and a control voltage VC being an output of the said circuit is fluctuated to a low level. When the voltage VC is decreased, an nMOS TRT9 of a basic amplifier circuit is fluctuated, the mutual conductance of the control voltage generating circuit is decreased and the mutual conductance of a TRT6 is increased. These changes act in the direction to cancel the fluctuation of the logic threshold value of the basic amplifier circuit. Thus, the fluctuation of the logic threshold value of the CMOS inverter is suppressed due to the characteristic fluctuation of the TRT9. |
