A Compact High-Efficiency Boost Converter With Time-Based Control, RHP Zero-Elimination, and Tracking Error Compensation

Time-based signal processing has been recently demonstrated to be more area- and power-efficient compared with traditional analog based, making it an interesting approach for the design of compact high-efficiency dc–dc converters for portable applications. This work presents a novel boost converter, with a time-based control, a scheme for right-half plane (RHP) zero mitigation requiring no extra power switch nor external capacitor, and a pulse frequency modulation (PFM) operating mode with steady-state error correction and seamless PFM-to-continuous conduction mode (CCM) transition. The prototype implemented in a 0.18-
$\mu$
m bipolar-CMOS-DMOS (BCD) process generates an output voltage of 5 V from an input voltage ranging between 2.5 and 4.5 V, and has an 800-mA load current capability. The controller area occupation is 0.27 mm
$^{2}$
and the quiescent current in CCM is 300
$\mu$
A for the controller and 40
$\mu$
A for the tracking error compensation. The peak efficiency is 96
$\%$
at 4.5-V input and above 90
$\%$
at light loads down to 50 mA current. Compared with a peak-current mode control, both the controller area and the current consumption of the proposed time-based architecture are lower by about 40%. The achieved closed-loop bandwidth of 130 kHz is six times larger than in a conventional boost converter with RHP zero.