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The flipped-voltage-follower-based low-dropout regulator (LDO) has drawn attention for its fast response and reduced complexity, while super source follower can be combined to push the pole at the gate of the pass device to high frequency. But the maximum load current and minimum load capacitance of this topology are limited, especially when the poles and zero from the SSF are omitted in previous designs. This paper proposes a solution to extend the ranges of the load current and load capacitance, by implementing a small feed-forward capacitor ($C_{F}$) and a damping factor control circuitry. In addition, a slew rate enhancement circuit is applied to reduce the voltage undershoot. The proposed LDO is verified in a 65-nm CMOS process with 0.008 mm2 active area. The measured voltage undershoot is 80 mV with a load steps from 100 μA to 50 mA with 2-ns edge times, with no external capacitor. And the maximum load capacitance can be extended to 2 nF. A figure-of-merit of 0.8 mV is achieved. [ABSTRACT FROM AUTHOR]

This paper presents a switched-capacitor (SC) bandgap reference (BGR) with second-order curvature compensation for ultra-low power systems. The gate-source voltage of a sub-threshold MOSFET is proposed to implement the second-order curvature compensation voltage in this work. And then, a SC network is used, not only to add the second-order voltage and the first-order one together, but also to fulfill the summing weight effectively and precisely. In this way, the silicon area and power consumption can be reduced simultaneously. Furthermore, the design methodology of summing weight is investigated, and thus the temperature coefficient (TC) can be significantly reduced. The proposed SC-BGR was implemented and simulated in a CMOS 0.18 μm process, the average output voltage is 426.1 mV, achieving a TC of 17.6 ppm/°C from −20 to 100 °C under a 0.5 V minimum supply voltage. With the help of the SC architecture, a small chip area of 0.0975 mm2 is achieved with only 37.8-nW power consumption. [ABSTRACT FROM AUTHOR]

Owing to its relatively high efficiency, extended transmission range, and less exposure to radio frequency radiation, near-field resonant wireless power transfer (R-WPT) has been widely used in consumer electronics and bio-implants. For most applications, a well-regulated output voltage is required against the coupling and loading variations, and thus a regulation scheme should be employed in an R-WPT system. To achieve an optimal receiver (RX) or overall efficiency, together with a reduced cost overhead, several regulation schemes have been proposed in recent years, where the regulation can be implemented at either the RX or transmitter (TX) side, or both. These regulation schemes have been reviewed and comprehensively discussed in this paper. Hence, the main contribution of this paper is to provide a guideline for designing the regulation scheme in R-WPT systems. Moreover, potential new topologies of regulation are investigated here. [ABSTRACT FROM AUTHOR]