A Multi-Mode DC-DC Converter for Direct Battery-to-Silicon High Tension Power Delivery in 65nm CMOS

We present a multi-mode DC-DC converter that directly takes the output of a Li-ion battery and converts it to on-chip voltages suitable for integrated electronics. The design in standard 65nm CMOS converts the Li-ion battery voltage that can vary between 4.2V to 2.8V directly to a internal V _DD voltage that ranges between 1.5V to 0.3V. The 65nm design safely handles the high voltage delivery while providing conversion ratios between 1 to 13. To maintain high efficiency throughout, the proposed DC-DC converter functions in three distinct modes - resonant, soft-switching and four-level-buck. We use a bond wire inductor (≈11nH) as the high Q passive for all three modes. The design uses core devices only. The converter handles load currents between 0.5-200mA (400X), achieves a peak efficiency of 86.6% and has a peak power density of 0.3W/mm ² . The prototype was fabricated in TSMC's 65nm GP CMOS.