A fully-integrated 0.18μm CMOS DC-DC step-down converter, using a bondwire spiral inductor

A fully-integrated DC-DC step-down converter in a 0.18 mum 1.8 V CMOS technology is realized, with a bondwire spiral inductor and integrated MOS and MIM capacitors. The converter is designed to generate an output voltage of 1.8 V out of a 3.6 V power supply. No external components are required. The maximum power conversion efficiency is 65 %, for a voltage conversion ratio of 0.5. This is a 23 % improvement compared to a linear regulator. Higher values are likely to be reached using a converter with external components, which is not the case here. Stacked transistors are used to cope with the high voltage. A novel control system based on a constant on/off-time keeps the output voltage constant at load conditions from 0 mW to 300 mW. The converter operates in discontinuous, asynchronous switching mode. The switching frequency ranges from 20 Hz to 140 MHz.

[1]  M. Steyaert,et al.  A fully-integrated 0.18µm CMOS DC-DC step-up converter, using a bondwire spiral inductor , 2007, ESSCIRC 2007 - 33rd European Solid-State Circuits Conference.

[2]  B. Bakkaloglu,et al.  A Multistage Interleaved Synchronous Buck Converter With Integrated Output Filter in 0.18 $\mu$m SiGe Process , 2007, IEEE Transactions on Power Electronics.

[3]  S. Narendra,et al.  A 233-MHz 80%-87% efficient four-phase DC-DC converter utilizing air-core inductors on package , 2005, IEEE Journal of Solid-State Circuits.

[4]  P.L. Chapman,et al.  Design of Low Power Monolithic DC-DC Buck Converter with Integrated Inductor , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[5]  B. Bakkaloglu,et al.  A Multi-Stage Interleaved Synchronous Buck Converter with Integrated Output Filter in a 0.18/spl mu/ SiGe process , 2006, 2006 IEEE International Solid State Circuits Conference - Digest of Technical Papers.

[6]  K. Inagaki,et al.  Stacked-Chip Implementation of On-Chip Buck Converter for Distributed Power Supply System in SiPs , 2007, IEEE Journal of Solid-State Circuits.

[7]  Brian Hu,et al.  A Highly Integrated Power Management IC for Advanced Mobile Applications , 2006, IEEE Custom Integrated Circuits Conference 2006.

[8]  Shahriar Mirabbasi,et al.  A 3GHz Switching DC-DC Converter Using Clock-Tree Charge-Recycling in 90nm CMOS with Integrated Output Filter , 2007, 2007 IEEE International Solid-State Circuits Conference. Digest of Technical Papers.