| 摘要 |
PROBLEM TO BE SOLVED: To provide an output buffer circuit having a linear characteristic enhanced more than that of an existing circuit. SOLUTION: A CMOS imager is placed on many rows and columns and a gain compensation circuit is placed to the respective columns. The gain compensation circuit includes a 1st source follower circuit that has PMOS transistors(TRs) 11, 12 and uses majority carriers with a 1st polarity to produce a 1st voltage gain and a 2nd source follower circuit that includes NMOS TRs 17, 18 and uses majority carriers with a 2nd polarity opposite to the 1st polarity to produce a voltage gain opposite to the 1st voltage gain. An input to the 2nd source follower circuit couples electronically with an output of the 1st source follower circuit, resulting that gain compensation is caused between the 1st and 2nd source follower circuits. A selection circuit is formed to activate the gain compensation circuit by a column selection signal.
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