| 摘要 |
PURPOSE:To miniaturize the system by connecting plural diffusion resistive elements in series between sources of two transistors (TRs), selecting each connecting point by a switch and impressing a negative power supply so as to attain accurate adjustment of an offset voltage. CONSTITUTION:Diffusion resistive elements r1-rn are connected in series between N-channel TRs 3, 4 constituting a load TR of a differential amplifier circuit, and each connecting point of the elements r1-rn is connected to a negative power supply by a selection switch SW. In the differential amplifier circuit constituted in this way, a proper switch SW between the elements r1-rn is turned on to combine the diffusion resistors thereby adjusting the offset voltage of the differential amplifier circuit. Moreover, the offset adjustment is conducted more accurately as the resistance value of each resistive element is small and the number of the resistive elements is larger. Thus, the miniaturization of the system is attained.
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