Inductor and TSV Design of 20-V Boost Converter for Low Power 3D Solid State Drive with NAND Flash Memories

Two essential technologies for a 3D Solid State Drive (3DSSD) with a boost converter are presented in this paper. The first topic is the spiral inductor design which determines the performance of the boost converter, and the second is the effect of TSV’s on the boost converter. These techniques are very important in achieving a 3D-SSD with a boost converter. In the design of the inductor, the on-board inductor from 250 nH to 320 nH is the best design feature that meets all requirements, including high output voltage above 20 V, fast rise time, low energy consumption, and area smaller than 25 mm2. The use of a boost converter with the proposed inductor leads to a reduction of the energy consumption during the write operation of the proposed 1.8-V 3D-SSD by 68% compared with the conventional 3.3-V 3D-SSD with the charge pump. The feasibility of 3DSSD’s with Through Silicon Vias (TSV’s) connections is also discussed. In order to maintain the advantages of the boost converter over the charge pump, the reduction of the parasitic resistance of TSV’s is very important. key words: SSD, boost converter, charge pump, inductor design, TSV’s