University of Michigan
Electrical & Computer Engineering
1301 Beal Ave., 2417C EECS
Ann Arbor, MI 48109
Tel: 734 763 4526
Fax: 734 763-4617
We developed an active decap circuit that significantly increases the effectiveness of decap in suppressing power supply fluctuations. The proposed circuit senses the supply drop and drives an amplified and inverted voltage fluctuation on the decap. The active decoupling circuit is powered by an external power supply. We studied the optimal allo¬cation of the total C4s/pads between this external power supply and the regular supply, as well as the optimal allocation of the total decoupling capacitance between actively switched and traditional passive decap. We demonstrated that the overhead of the pro¬posed method is small compared to the area of decaps. Using the proposed method, the maximum supply drop is reduced by 45% compared to the use of only traditional decap, corresponding to an increase in the effective decap of approximately 8X at the resonance frequency.
Our recent work involves investigation and design of more effective active voltage regulator-based techniques for improving the robustness of supply voltage to high frequency load-current transients.
Sanjay Pant, David Blaauw, “An Active Decoupling Capacitance Circuit for Inductive Noise Suppression in Power Supply Networks,” IEEE International Conference on Computer Design (ICCD), October 2006 ©IEEE