US 2009/0015313 A1Published application

Level Shift Circuit and Semiconductor Integrated Circuit Including the Same

OwnerTsuyoshi Matsushitainventor

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Abstract

In a level shift circuit, including two Nch transistors Tn1, Tn2 receiving a pair of complementary input signals and two Pch Transistors Tp1, Tp2 of which gate terminals are cross-coupled to each other, nodes A and B as the drains of the two Nch transistors Tn1, Tn2 operating in reverse to each other are connected together with a resistance Tp3. The resistance Tp3, constructed of a Pch transistor, is grounded at its gate to be in the normally ON state. For example, when the Nch transistors Tn1 and Tn2 go ON and OFF, respectively, a current initially flows from the high-potential node A through the resistance Tp3 to the low-potential node B, raising the potential at the low-potential node B. Thus, the potential rise at the node B is sped up compared with the case that only the Pch transistor Tp2 becoming ON contributes to the potential rise. This enables high-speed operation of the level shift circuit with a small number of elements.

Claims8

Dependent claims

A level shift circuit comprising:

first and second P-channel transistors of which sources are connected to a high-voltage power supply;
and
first and second N-channel transistors of which sources are grounded,
wherein complementary input signals in phase with and in opposite phase to an input signal from a low power-supply voltage operating circuit are respectively inputted to gates of the first and second N-channel transistors,
a drain of the first N-channel transistor is connected to a drain of the first P-channel transistor and a gate of the second P-channel transistor,
a drain of the second N-channel transistor is connected to a drain of the second P-channel transistor and a gate of the first P-channel transistor,
the level shift circuit further comprises a resistance connecting the drain of the first N-channel transistor with the drain of the second N-channel transistor, and
the drain of the second N-channel transistor serves as an output terminal to a high power-supply voltage operating circuit.

5 more elements

Dependencies are inferred from the claim text.