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

Abstract

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.

Differential signal balancer embedded in silicon LSI as smallest common-mode filter combined bifilar coupling inductors and stacked delay lines

“…Taking advantage of this feature, we have developed a DSB embedded in metal wiring layers (DSB-EIM) on the 180 nm standard CMOS LSI with an area of 120 × 250 μm 2 which is much smaller than other new CMFs. 29) The previously developed DSB-EIM (DSBE1) was the first implementation of DSB on LSI wiring layers and only supports removing the Wi-Fi RFI of the 2.4 GHz band.…”