Compact differential signal balancer embedded in metal wiring layers of silicon LSI for common mode noise filtering

The differential signal balancer (DSB) is a discrete common mode filter component using a low temperature co-fired ceramic (LTCC) process in which non-magnetic materials are employed. In this paper, we have developed the new DSB embedded in metal wiring layers of silicon LSI for achieving the multiple ultra-high-speed differential transmission exceeding 10 Gb s−1 between LSIs. While the spiral inductors in the silicon CMOS process are affected by the substrate loss and conductor resistance with the thinner thicknesses for both metal and dielectric layers, its lumped circuit parameters are optimized well, and the obtained characteristics are almost comparable with that of the conventional DSB using LTCC. It has approximately −10 dB attenuation of common mode noise at 2.4 GHz with very small size of 120 μm × 250 μm and volume size of about 1/6000 compared to the conventional DSB.