US Patent 7408389 Output circuit with signal level shift

In a level shifting circuit, by supplying current to a gate resistor, a bias is applied to a gate of a transistor. Further, current corresponding to the current which flowed through the gate resistor flows through a first current path of a current mirror circuit, and the current mirror circuit functions to supply current corresponding to the current which flowed through the gate resistor to a source of the transistor. Therefore, current corresponding to the current which flowed through the gate resistor is supplied to an output resistor and it is possible to output a voltage in response to a voltage drop related to the supplied current. Therefore, level shifting can be performed to an input signal for outputting.