Output Stages for Integrated DC-DC Converters and Power ICs

Integrated switched mode power supplies and incorporate large amount of complex mixed-signal control circuits as well as the power transistors on the same die. CMOS compatibility is a very important consideration when designing monolithic DC-DC converters. This paper examines the different power output stage designs and identifies the key device characteristics such as on-resistance, gate capacitance, switching speed that ensure optimized power conversion efficiencies. An integrated 1W, 4MHz multi-mode DC-DC converter with Segmented Output Stage and a peak power conversion efficiency of 88% is used to illustrate various design trade-offs.