Design of an integrated single-input dual-output 3-switch buck converter based on sliding mode control

This paper presents the design, implementation, and testing of a proof-of-concept monolithic single-input dual-output buck converter. The proposed architecture implements an analog hysteretic controller. This avoids the use of extra circuitry to generate a dedicated reference carrier signal to create the pulse-width modulated waveform, thus saving area, and reducing static power consumption. Furthermore, the proposed topology implements only three switches (instead of four switches in conventional solutions), and can save additional silicon area with proper design of the power switches in the voltage regulator. The IC prototype was fabricated in standard 0.5 μm CMOS technology (VTHN = 0.78 V, VTHP = −0.93 V), operates with a single voltage supply of 1.8 V, generates 1.2 and 0.9 V output-voltage levels, and supplies a maximum total current of 200 mA (100 mA provided by each output), reaching up to 88 % efficiency.