(An) error-based controlled single-inductor multiple-output DC-DC buck converter

Abstract

An error-based control method is proposed for a single-inductor multiple-output (SIMO) converter that maintains high efficiency under various load conditions. A peak efficiency of 88.7% was achieved with one output $(I_{O1})$ of 5 mA, while the other outputs are at 432 mA. A hybrid topology composed of a switching con-verter and a linear regulator is also presented for fast load transient response. The proposed SIMO buck con-verter was fabricated with a 1P4M 0.35-um BCD process and has 10 independently regulated outputs. The measured load transient waveform shows cross regulation of 0.1 mV/mA and a load transient of 0.17 mV/mA. This was achieved under load transient conditions for one output $(I_{O9})$ in between 1 mA and 100 mA with the other outputs at 422 mA. The paper is organized as follows. The conventional comparator-based control method is discussed in Chapter 2. Then, the proposed EBC and a time-based multi-input comparator used for the control method are presented in Chapter . A hybrid topology is presented in Chapter 4 to improve cross regulation in transient conditions. In Chapter 5, the circuit implementations of the proposed EBC and hybrid topology are discussed. The measurement results and a performance comparison are provided in Chapter 6. Finally, the conclusion follows in Chapter 7.