Ming-Hsin Huang

Sub-1 V Input Single-Inductor Dual-Output (SIDO) DC–DC Converter With Adaptive Load-Tracking Control (ALTC) for Single-Cell-Powered Systems

In this paper, a sub-1 V input single-inductor dual-output (SIDO) dc-dc converter with an adaptive load-tracking control (ALTC) technology is proposed for single-cell-powered portable devices. Having a minimal number of switches and an optimum current sequence, the proposed ALTC technique adaptively and accurately adjusts storage energy in the form of inductor current according to the actual load condition, without wasting surplus charge and without increasing cross regulation. Moreover, a current-mode ring oscillator with a self-bias current source circuit, in place of the conventional start-up ring oscillator, is proposed to produce a nearly constant system clock for the requirement of sub-1 V start-up procedure. Because the proposed current-mode ring oscillator operates between the start-up process and steady state of the SIDO dc-dc converter, its simplified design efficiently addresses the high switching frequency losses at sub-1 V start-up procedure, reducing chip area and power consumption. The proposed sub-1 V input SIDO dc-dc converter was fabricated via Taiwan Semiconductor Manufacturing Company 0.25 μm 2.5 V/5 V Bipolar-CMOS-DMOS process, and the experimental results show high efficiency of 92% with a good cross regulation smaller than 10 mV.

Energy-Recycling (ER) Technique for a Direct-Lit Intelligent Power Management Backlight Unit (BLU)

A field-sequential-color (FSC) liquid crystal display (LCD) technique with a direct-lit red, green, and blue LED backlight driver is proposed to achieve low weight, thin, perfect image quality, and low-power consumption of LCD television. The FSC technique performs a pseudorandom color sequence in the spatial and temporal domains to reduce color-breakup and motion-blur effects. The direct-lit RGB-LED backlight driver increases brightness, contrast, and uniformity due to the removal of a color filter. In this paper, the proposed FCS-LCD controller uses a single LED driver to switch the driving voltage alternatively between 36 V for driving 12-series G- or B-LEDs and 24 V for 12-series R-LEDs. The proposed energy-recycling technique can harvest the extra energy when the driving voltage switches from 36 to 24 V. Experimental results show that energy saving is higher than 17% of the conventional driving method.

A single-inductor multiple positive and negative outputs (SIMPNO) converter with a vector current control mode for electronic paper displays (EPDs)

A single-inductor multiple positive- and negativeoutput (SIMPNO) converter provides a compact-size and high efficiency solution for electronic paper displays (EPDs) system. With the single inductor multiple output structure, an adaptive current control methodology with the proposed vector current control mode (VCCM) can wisely minimize the current tolerance to be smaller than 10 % between input and all outputs. Additionally, owing to the VCCM technique for adequate inductor current control, the cross regulation is smaller than 0.35 V/A. The test chip was fabricated by 0.25 μm BCD process with a peak value of 90 % at heavy loads.

A high efficiency and compact size 65nm power management module with 1.2v low-voltage PWM controller for UWB system application

This 65 nm power management module with 1.2 V low-voltage PWM controller aims to integrate with ultra-wideband (UWB) system to get high efficiency and compact size. The on-chip pre-regulator with power conditioning circuit provides a constant and noiseless supply voltage. Thus, the voltage variation of battery has less effect on the low-voltage PWM controller. The proposed compensation enhancement multistage amplifier (CEMA) increases system loop gain and stabilizes the system without off-chip compensation circuit. With excellent line/load transient response, the proposed power management has the highest efficiency about 92% and 0.995 mm2 silicon die area.

Sub-1V input single-inductor dual-output (SIDO) DC-DC converter with adaptive load-tracking control (ALTC) for single-cell-powered system

In this paper, a sub-1V input single-inductor dual-output (SIDO) DC-DC converter with an adaptive load-tracking control (ALTC) technique is proposed for single-cell-powered portable devices. The ALTC technique adaptively and accurately adjusts storage charge in form of the inductor current according to actual load condition without wasting surplus charge and increasing cross-regulation through the use of minimized the number of switch and optimum current sequence. A current-mode ring oscillator with a self-bias current source (SBCS) circuit is proposed to replace conventional startup oscillator to produce a nearly constant system clock. The test chip was fabricated by TSMC 0.25 µm 2.5 V/5 V BCD process and experimental results show a high efficiency of 92 % and a cross- regulation smaller than 10 mV.

A 50nA quiescent current asynchronous digital-LDO with PLL-modulated fast-DVS power management in 40nm CMOS for 5.6 times MIPS performance

A 50nA quiescent current asynchronous digital-LDO (DLDO) integrated with the PLL-modulated switching regulator (SWR) exhibits the hybrid power management operation. The proposed bidirectional asynchronous wave pipeline (BAWP) in the asynchronous DLDO realizes the Fast-DVS (F-DVS) operation within tens of nano-seconds. The SWR with the leading phase amplifier achieves on-the-fly DVS and 94% peak efficiency, as well as improves 5.6 times MIPS performance through hybrid operation. The fabricated chip occupies 1.04mm2 in 40nm CMOS.

An energy-recycling (ER) technique for field color sequential LCD backlight driving

An energy-recycling (ER) technique has been proposed to implement high power conversion efficiency and low cost solution of field color sequential (FCS) LEDs backlight driving. One recycling capacitor CR and one power-transistor MR are added to synchronous boost converter to compose the ER function. When the output voltage of FCS-LEDs backlight driver switches from 40V to 26V for driving RGB LEDs during related time interval, ER technique stops to boost input voltage and switches to recycle energy from output terminal to the recycling capacitor CR. Thus, the output voltage can be rapidly switched between two different voltage levels with minimum power losses. The proposed ER technique has been fabricated by TSMC 40V BCD process. The experimental results demonstrate fast and efficient output voltage tracking performance is achieved by the proposed ER technique.

43.2: A Charge-Reservoir with Buck-Store and Boost-Restore (BSBR) Technique for High Efficient Conversion and Low Cost Solution of RGB LED Display Panels

A boost converter with buck-store and boost-restore(BSBR) technique fabricated by 0.25μm CMOS BCD process can provide different supply voltages to drive series RGB LEDs in sequence for reducing the power consumption on the constant current generator. The proposed technique not only stores and restores extra charge during the transient time of the reference tracking response to improve the efficiency but also enhances the reference tracking response to greatly reduce load transition time. Experimental results show that the period of reference-tracking response can be improved. When the load current is 100mA, the periods of reference down-tracking and up-tracking are smaller than 10μs and 20μs, respectively. Furthermore, this technique also can provide a regulated voltage to drive the sub-block implemented in the LCD system. The maximum efficiency of charge recycling is up to 94% and the maximum efficiency of this boost converter is 92.5%. Experimental results demonstrate fast and efficient reference tracking performance is achieved by the proposed BSBR technique.

26.2: A Single‐Inductor Multi‐Output Converter with Multi‐Vector Current Control in Power‐saving Driving Skill of Electronic Paper Displays (EPDs)

Electronic paper display (EPD) shows the trend of state-of-the-art display technique. It not only holds image/text without consuming energy but also presents thin and flexibility like ordinary paper. Single-inductor multi-output (SIMO) converter, with innovative multi-vector current-control methodology, precisely tracks and quantifies the actual demanded-energy and addresses excessive-energy for power-efficient and space-minimized requirements of EPDs. The testing chip occupies 0.45 mm2 in 0.25 μm CMOS technology and achieves the power conversion efficiency larger than 85 % at the order of 0.5 m W output power.

29.4: A RGB-LEDs Backlight Driver with Field Color Sequential (FCS) and Energy-Recycling (ER) Techniques for Minimum Power Loss on LCD System

A field-color-sequential (FCS) LCD technique with a direct-lit red, green, and blue (RGB) light-emitting diode (LED) backlight driver is proposed to achieve the demands of weightless, thickness, perfect image-quality, and low power-consumption of liquid crystal display (LCD) television (TV). In this paper, the proposed FCS-LCD controller uses only one single LED driver to alternatively switch driving voltage between 40V for driving 12-serie G- or B-LEDs and 26V for 12-serie R-LEDs. In addition, In order to, the proposed energy-recycling (ER) technique can harvest the extra energy when the driving voltage switches from 40V to 26V. Experimental result shows the energy-saving be higher than 17% of the conventional driving method.