| 摘要 |
PROBLEM TO BE SOLVED: To relieve a voltage difference, to speed up operation speed and to reduce power consumption by once signal-converting to an intermediate signal in an integrated circuit having multiple power sources. SOLUTION: When the signal of a power source voltage E1 system is inputted to the power source E2 of high potential and it is converted, it is necessary to considerably enlarge the ratios of the conductance constantsβof FET in an E1 system and an E2 system for normally operating level shift. When E2 =5V and E1 =0V and other prescribed values are decided and calculation is executed, theβratio exceeds 500. When the EM system of intermediate potential is provided between E1 and E2 , the signal of the E1 system is converted into the signal of the EM system, and it is inputted to the E2 system. Theβratios of FET in the respective systems at the time of conversion become about 20 and 40, and theβratios can considerably be reduced. Thus, a level shift operation can reasonably be executed in a conversion process and power consumption can be reduced without the need of large MOSFET.
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