New Compact CMOS Li-Ion Battery Charger Using Charge-Pump Technique for Portable Applications

Dept. of Electron. Eng., Nat. Taipei Univ.
Circuits and Systems I: Regular Papers, IEEE Transactions on (Impact Factor: 2.3). 05/2007; 54(4):705 - 712. DOI: 10.1109/TCSI.2007.890605
Source: IEEE Xplore

ABSTRACT This paper presents a new compact CMOS Li-Ion battery charger for portable applications that uses a charge-pump technique. The proposed charger features a small chip size and a simple circuit structure. Additionally, it provides basic functions with voltage/current detection, end-of-charge detection, and charging speed control. The charger operates in dual-mode and is supported in the trickle/large constant-current mode to constant-voltage mode with different charging rates. This charger is implemented using a TSMC 0.35-mum CMOS process with a 5-V power supply. The output voltage is almost 4.2 V, and the maximum charging current reaches 700 mA. It has 67.89% power efficiency, 837-mW chip power dissipation, and only 1.455times1.348 mm2 in chip area including pads

  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents an ultra-low power, fully integrated solar energy harvester circuit for autonomous microsystems. The proposed circuit harvests solar energy from a micro-power photovoltaic module and stores the harvested energy in a miniaturized thin film Li-Ion microbattery, using a highly area- and power-efficient power management circuit. As neither inductor, nor large pumping capacitors have been used in this circuit, it occupies less area comparing to conventional inductive and switched-capacitor DC-DC converters. In addition, thanks to low power design of this circuit, it achieves more than 94% efficiency during battery charging. Even under reduced light intensity, when the harvested energy is only a few tens of microwatts, more than 92% efficiency is achievable. The proposed microsystem has been implemented in a 0.18μm CMOS process and occupies a core area of only 0.12mm2. This circuit features a low power consumption of 270nW in average.
    Electronics, Circuits and Systems (ICECS), 2012 19th IEEE International Conference on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: Proposed continuously built-in resistor detector (CBIRD) monitors the built-in resistance (BIR) of the Li-Ion batteries for achieving fast charging process. Owing to the detection of the battery built-in resistance in real-time, the transition from the constant-current (CC) mode to the constant-voltage (CV) mode can be postponed to have large energy storing in the battery, Thus, the charging time of the switching-based charger can be effectively reduced. The CBIRD is composed of four analog circuits, which are the differentiator, the subtraction sample-and-hole (S/H), analog multiplication-division unit (AMDU), and voltage adder for accurate BIR detection. Thus, the proposed switching-based charger with the CBIRD has 45% charging time improvement for Li-ion batteries.
    ESSCIRC (ESSCIRC), 2013 Proceedings of the; 01/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: This work proposes a novel battery charger circuit with an improved parallel-loaded resonant converter use in rechargeable batteries in mobile power applications. The proposed topology is composed of an improved parallel-loaded resonant inverter and a bridge rectifier. The output voltage of the improved parallel-loaded resonant converter is filtered by an electrolytic capacitor. This topology has advantages over the traditional parallel-loaded resonant converter of smaller size, lower weight and lower cost. The operating principles of the proposed charger circuit are thoroughly analyzed. A prototype charger circuit with the improved parallel-loaded resonant converter implemented for a 12V 12000mAh rechargeable battery of mobile power is constructed and tested to verify the theoretical predictions. The measured energy conversion efficiency of the improved parallel-loaded resonant topology reaches up to 91.2%. The test results demonstrate that the novel topology provides a satisfactory performance. The improved parallel-loaded resonant converter has great potential for use in power-related devices in electronic products, such as standby power supplies for laptop computers, communication equipment, consumer electronics, and telecom power supplies.
    2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE); 06/2014


Available from