Fully integrated switched-capacitor voltage converter with regulated output

摘要

The paper presents the integrated circuit (IC) of the inductorless switched-mode DC-DC voltage converter. The converter is based on a novel multiphase switched-capacitor architecture. It uses reconfigurable charge-pump circuits and a multiloop discrete and continuous time control technique. The control unit performs a converter topology selection, a value of switched capacitors selection as well as a conversion frequency regulation. The chip also comprises a built-in low-dropout linear regulator. The on-chip reference of 1.0 V is powered by a PSRR-enhancing pre-regulator. The core of bandgap reference uses a dynamic threshold voltage MOSFET (DTMOS) transistors instead of generally used diode-connected vertical p-n-p bipolar transistors. The IC has been implemented in a commercially available 180 nm CMOS technology with five metal layers and stacked metal-insulator-metal capacitors. It is intended for use as a standalong IC for converting power rail voltages or lithium electrochemical cell voltages 2.8 V-5.5 V conversion into power supply voltages 1.2 V-3.3 V of the modern microcontrollers and other low-voltage ICs. It also may be used as a embedded IP block of a system-on-chip. The paper discusses features of regulation in a multiphase system over a wide range of input and output voltages and load currents. It also presents the results of the IC samples evaluation.