| 摘要 |
PROBLEM TO BE SOLVED: To convert a level by using a logic gate at an output terminal of a function block in the inside of a chip, without the need for addition of a level shifter. SOLUTION: A logic interface circuit consists of a logic gate provided with a transistor(TR) P1, that pulls up the level at an output terminal OUT and a TR N1 that pulls down the level at the output terminal OUT, a reverse current flow preventing circuit N2 that is connected between a 1st power supply voltage point VDD1 and the TR P1 to prevent a reverse flow from the P1 to the VDD1, a circuit P2 that is connected in parallel with the TR N2 and pre-charges a common point between the circuit N2 and the TR P1 in response to a signal from the output terminal OUT, and a circuit P3 that is connected between the VDD2 and the OUT, is turned off in response to the VDD1 when the VDD1 is higher than the VDD2 to prevent reverse flow from the OUT to the VDD2, and turned on in response to the input signal IN when it is smaller, to boost the level of the output terminal OUT to the VDD2.
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