A 50MHz 5V 3W 90% efficiency 3-level buck converter with real-time calibration and wide output range for fast-DVS in 65nm CMOS

In this paper, a 50-MHz 5-V input 3-W output 3-level buck converter is presented. A real-time flying capacitor (C
F
) calibration is proposed to ensure a constant V
g
/2 voltage across the C
F
, which is essential to ensure the reliability and maintain the advantages of 3-level converters. A 0.6–4.2V wide output range, a 90% peak efficiency and a 23–29ns/V reference tracking response are observed in measurements with 65nm process. A significantly reduced V
O
ripple is achieved after enabling the proposed calibration.