| 摘要 |
PURPOSE:To improve detection sensitivity and to obtain an output stable to fluctuations of the power source, by connecting a couple of transistors (TR), controlled on the basis of levels of a couple of data bus lines, in parallel between the common connection point of a couple of inverters and the reference potential point. CONSTITUTION:When TRs Q13 and Q14 are controlled via bus lines DB' and - DB', TRs Q13 and Q14 increase in conductivity according to the rise of power source VDD and a rise in potential at common connection point N1 of a couple of inverters 11 and 12 is stopped. Therefore, outputs SD and -SD are both stabilized by being stopped from varying in phase. Although the level of common connection point N1 is determined by ratio gm of TRs Q11-Q14, its value never depens upon the magnitude of the differential component between bus lines DB' and -DB'. As the current TR Q13 or Q14 increases according to the level of bus line DB owing to the complementary characteristics between levels DB' and -DB', the other decreases and the total of the both is fixed. Then, the parallel circuit of TRs Q13 and Q14, when the side of earth point VSS is viewed from point N1, is considered to be a constant current source and the detection sensitivity is improved more than a sense amplifier having point N1 connected direct to VSS. |
