Summary: A mapping circuit in order to have a wider input dynamic range is proposed. MOSFET's connecting between power supply lines are employed to construct the mapping circuit. SPICE simulation is shown to evaluate the proposed circuits. With the proposed mapping circuit, two-MOSFET subtractor has a rail-to-rail input voltage. As an application, an OTA consisting of subtractors is realized by employing the proposed mapping circuits to have a rail-to-rail input voltage range.