COMPLEMENTARY SOURCE FOLLOWER CIRCUIT

摘要

PROBLEM TO BE SOLVED: To obtain a circuit avoiding generating non-linearity even to the voltage operation of a low power source by inputting a potential difference equal to or smaller than a specific value between power source terminals, allowing an N-type FET to have negative threshold voltage and a P-type FET to have positive threshold voltage and using the positive and negative threshold values having absolute values smaller than applying power voltage. SOLUTION: A complementary source follower circuit connects one of the source/drain terminals of an N-type FET 10 to a power source terminal 12 and one of the source/drain terminals of a P-type FET 11 to a ground terminal 13. There is a relation where the sum of VN1 being a point obtained by extrapolating the curve of the current of the FET 10 to zero current and|VtN|is equal to Vout and a difference between VP1 being a point obtained by extrapolating the curve of the current IP of the FET 11 to zero current and Vdd+|VtP|is equal to (Vdd-Vout). In this case, Vtn and Vtp express the threshold voltage of the N-type and P-type FETs 10 and 11.