Patent ID: 6433582
Filing Date: 2002-08-13
Classification: H03K

Abstract:
A voltage level shifter circuit, comprising:a first transistor having a source, a drain, a backgate, and a gate; a second transistor having a source, a drain, a backgate, and a gate; a switching section for receiving an input signal and changing respective voltages to be applied to first and second nodes, wherein one of the source and the drain of each of the first and second transistors is connected to a third node, the backgate of each of the first and second transistors is connected to the third node, the other of the source and the drain of the first transistor and the gate of the second transistor are connected to the first node, and the other of the source and the drain of the second transistor and the gate of the first transistor are connected to the second node, the voltage level shifter circuit further comprising: a resistance equivalent element having first and second ends, a high voltage being applied to the first end, and the second end being connected to the third node, and having a resistance such that a total resistance between the first end and the second node is larger than a total resistance between the input terminal and the second node since both a transistor and a resistor are coupled between a first end and the second node while only a transistor is coupled between the input terminal and the second node, wherein during operation of the voltage level shifter circuit an input signal transitions from a voltage Vcc to a reference voltage Vss, the resistance equivalent element restricts current flow and the second transistor is cutoff.