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We demonstrate an integrated buck dc-dc converter for multi-V/sub CC/ microprocessors. At nominal conditions, the converter produces a 0.9-V output from a 1.2-V input. The circuit was implemented in a 90-nm CMOS technology. By operating at high switching frequency of 100 to 317 MHz with four-phase topology and fast hysteretic control, we reduced inductor and capacitor sizes by three orders of magnitude compared to previously published dc-dc converters. This eliminated the need for the inductor magnetic core and enabled integration of the output decoupling capacitor on-chip. The converter achieves 80%-87% efficiency and 10% peak-to-peak output noise for a 0.3-A output current and 2.5-nF decoupling capacitance. A forward body bias of 500 mV applied to PMOS transistors in the bridge improves efficiency by 0.5%-1%.

We demonstrate an integrated buck DC-DC converter implemented in a 90nm CMOS technology for multi-Vcc microprocessors. High switching frequency (100-317MHz), 4-phase topology, and fast hysteretic control reduce inductor and capacitor sizes by 1000x, thereby enabling off-chip inductors with no magnetic core and an on-chip decoupling capacitor. The converter achieves 80-87.7% efficiency and 10% peak-to-peak output noise.