| 摘要 |
PROBLEM TO BE SOLVED: To reduce the effect of characteristic fluctuation by the substrate bias effect by decreasing a current corresponding to a difference inverting input voltages among 1st and 2nd differential input voltages from a current corresponding to a difference between noninverting input voltages in 1st and 2nd differential input voltages so as to improve the linearity. SOLUTION: Two pairs of differential input voltages (VA1, VA2) and (VB1, VB2) are converted into two pairs of differential voltages (ΔA1,ΔA2) and (ΔB1,ΔB2) by voltage converters H1, H2 whose output voltage depends only on an input voltage level. Voltages between noninverting output terminals and between inverting output terminals having outputs of two pairs of differential voltagesΔA=ΔA1-ΔA2 andΔB=ΔB1-ΔB2 are given to voltage current converters G1, G2 whose amplification factor is constant at an input voltage amplitude around zero, where the voltages are converted into two pairs of differential currents. Then the two pairs of differential currents are given to a current voltage converter R, where output voltages nearly proportional to differences of the two pairs of differential currents are obtained. Thus differential difference amplifier is configured.
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