Patent ID: 7545172

Claim:
A voltage converting device for receiving a first input signal having a first high input voltage and a first low input voltage and a second input signal having a second high input voltage and a second low input voltage, said first high input voltage having a relatively high voltage level and said first low input voltage having a relatively low voltage level, and said second high input voltage having a relatively high voltage level and said second low input voltage having a relatively low voltage level, wherein said voltage converting device converts at least one of said first high input voltage and said first low input voltage and outputs said first input signal having a converted voltage level as a first output signal and converts at least one of said second high input voltage and said second low input voltage and outputs said second input signal having a converted voltage level as a second output signal, wherein said voltage converting device comprises: a first input portion receiving said first input signal; a first output portion outputting said first output signal; a second input portion receiving said second input signal; a second output portion outputting said second output signal; and a voltage converting circuit converting at least one of said first high input voltage and said first low input voltage and at least one of said second high input voltage and said second low input voltage, and wherein said voltage converting circuit comprises a first voltage dropping circuit dropping a voltage on a first node located between said first input portion and said first output portion to ground voltage before changing from a state in which said first input portion is disconnected from said first node to a state in which said first input portion is connected to said first node; and a second voltage dropping circuit dropping a voltage on a second node located between said second input portion and said second output portion to ground voltage before changing from a state in which said second input portion is disconnected from said second node to a state in which said second input portion is connected to said second node.