Patent ID: 7830182

Claim:
An electronic circuit comprising: a first circuit which operates at a first difference voltage between a first voltage of a first power source and a second voltage of a second power source, the second voltage being different from the first voltage; and a source-grounded amplifying circuit which operates at a second difference voltage between the second voltage of the second power source and a third voltage of a third power source, the third voltage being lower than the first voltage, and wherein the source-grounded amplifying circuit is coupled to an output of the first circuit, the first circuit providing a comparator function and including; first and second field effect transistors which respectively include sources connected commonly with each other and gates to which first and second input voltages are supplied respectively; a constant current source interposed between a common node connected between the sources of the first and second field effect transistors and the first power source; third and fourth field effect transistors which respectively include sources connected to the second power source, gates connected to a drain of the first field effect transistor, and drains connected to respective drains of the first and second field effect transistors; and a fifth field effect transistor which includes a source connected to a gate and a drain of the third field effect transistor, a drain connected to a node connected between the respective drains of the second and fourth field effect transistors, and a gate connected to the node, wherein a voltage of the node connected between the respective drains of the second and fourth field effect transistors is output to the source-grounded amplifying circuit as a signal showing a result of comparison between the first and second input voltages.