A 400uW, 4.7-6.4GHz 45nm CMOS VCO with active area underneath its Above-IC Inductor

A 400uW, 4.7-6.4GHz 45nm CMOS VCO with active area underneath its Above-IC Inductor ■

Jonathan Borremans, Jonathan Borremans, Jonathan Borremans, G. Carchon, G. Carchon, G. Carchon, Piet Wambacq, Piet Wambacq, Piet Wambacq, Maarten Kuijk, Maarten Kuijk, Maarten Kuijk, S. Decoutere, S. Decoutere, S. Decoutere

Abstract ■

A 4.7-to-6.4GHz VCO is designed in 45nm bulk CMOS using an Above-IC inductor on top of the active circuitry, yielding 28\% area reduction. The inductor is shielded from the circuitry, using the top metal layers of the CMOS back-end, which enables the proposed 3D integration for low-cost performance extension. The fully integrated VCO consumes just 400uW, achieves a FoM of 185dB, and occupies and area of only 0.12mm2.