Se Un Shin

The number of mobile device users increases every year. Each mobile device is usually equipped with a Li-ion battery having voltage that varies from a minimum of 2.7V to a maximum of 4.2V. Therefore, as the battery voltage decreases with time, a DC-DC converter is required for a regulated supply lower or higher than the battery voltage. A simple buck converter is not suited for this case, since step-up conversion is not available [1]. Instead, a non-inverting buck-boost converter can be a soluti

This article proposes a new boost converter topology called dual-path step-up dc-dc converter (DPUC). Unlike the conventional boost converter (CBC), the DPUC has a hybrid structure using one inductor and one flying capacitor to make dual current delivery paths. This allows continuous current delivering to the output, reducing both the dc level of the inductor current and the output voltage ripple. Therefore, the DPUC has higher efficiency and smaller output voltage ripple than those of the CBC.

DC-DC boost converters are widely used to increase the supply voltage in various applications, including LED drivers, energy harvesting, etc. [1-5]. The conventional boost converter (CBC) is shown in Fig. 27.5.1, where the switches S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> and S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> are turned on and off alternately at φ <sub xmlns:mml=

This letter proposes a loop-free autocalibration technique for self-balancing of flying capacitors in a three-level dc-dc buck converter. The proposed converter utilizes a dual-path power stage with balancing switches that adaptively short flying capacitors at de-energizing phases. Thus, the dual-path three-level converter ensures that flying capacitor voltages are self-balanced at half the input voltage without using additional feedback calibration loops, leading to robust operation and competi

Lithium-ion batteries are generally used in mobile devices, but the voltage range of the battery varies from 2.7 to 4.2V. To provide a mid-3V-range output from the battery, a converter capable of step-up/down-conversion is necessary. For this purpose, non-inverting buck-boost topologies with multimode control [1-3] have been widely used. However, they have limited efficiency slightly higher than 90%, which comes from the fact that a main current path always encompasses two switches. To increase

This article proposes a resonant voltage mode receiver (RVM-Rx) as a new topology of a wireless power receiver for battery charging. With a resonant capacitor interleaving scheme, an LC tank in the receiver can always be configured and isolated from the output, leading to optimal power transfer regardless of the operation phase. Thus, the power transfer efficiency is not sensitive to load conditions, such as battery voltage variation. In the RVM-Rx, a diode-based voltage peak time detection (VPT

This article proposes a bandgap reference (BGR) recursive low-dropout (LDO) regulator chip that achieves a high power supply rejection (PSR) in the low- to mid-frequency range. The presented LDO design enables the total PSR of LDO to be free from the finite ripple-rejection of the BGR circuit, resulting in low design complexity and low power consumption. To improve the PSR further, the gate buffer is modified to provide an additional ripple feedforward cancellation. The modified gate buffer also

This article proposes a series- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> resonant current mode receiver (RCM R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> ) for wirelessly powered battery chargers. With a series- <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> scheme, the RCM R <sub xmlns:mml="http://www.w3.org/1998/Ma

Reducing the number of large external components, especially inductors, is a very important issue for Power-Management ICs (PMICs). Single-Inductor Multiple-Output (SIMO) converters are excellent candidates to meet this requirement [1-3]. However, there are several issues with SIMO converters, such as cross regulation, instability and inefficiency at light load. Under normal load conditions, comparator-based controlled SIMO converters [1,2] show good cross regulation performance due to the fast

Wireless power transfer (WPT) has been widely adopted in various applications, such as biomedical implants and wireless sensors. A conventional voltage-mode receiver (VM-RX) uses a rectifier or a doubler for AC-DC conversion [1,2]. This requires a sufficiently large input power (P, <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</sub> ) inducing a large voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1

The energy harvesting interface circuit is proposed for wind-driven triboelectric nanogenerator (WD-TENG). To extract power from the WD-TENG maximally and deliver power to the output (battery) efficiently, a rectifier-reusing bias-flip (RRBF) technique and a multiphase reconfigurable switched-capacitor converter (MRSCC) are developed. In the RRBF, the low-side switches of the rectifier are reused as switches for bias-flip without additional components. The MRSCC delivers power to the battery eff

The issues of a single-inductor multiple-output DC-DC converter were studied. Poor cross regulation, low efficiency, low current capability, and large ripple are the major disadvantages of the single-inductor multiple-output converter compared with a conventional DC-DC converter. Several studies to overcome these problems are introduced in this paper.

In this article, a three-level current-mode boost converter with a fully state-based phase selection (FSPS) technique is presented. The proposed FSPS technique selects the operation phase adaptively to ensure the voltage across the flying capacitor ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{\mathrm {CF}}$ </tex-math></inline-formula> ) to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML"

This paper presents a $1.7 \times 4.1 \times 2$ mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> pH sensor that is a fully integrated, stand-alone and implantable system. Instead of a bulky cm size Ag/AgCl electrode, we use a mm-size integrated platinum electrode, and differential sensing using ISFET and REFET pair to compensate for unstable fluid potential. We also propose a drift compensation technique in which the leakage from the sourc