Power Management Chip Research Articles

Design of a Step-down DC-DC Converter ASIC Applied to Portable Electronic Products

Using CSMC 0.5μm process model, a Step-Down DC-DC converter ASIC applied to portable electronic products was designed. The peak current-mode control PWM with slope compensation was adopted in the power management chip to improve the dynamic response speed of the system; the error amplifier and PWM comparator was redesigned to improve the response speed and stability of the chip; the over-current protection function was included in the peak current sampling circuit; in addition, the circuit with the pulse-skipping mode reduce the battery energy loss. Capable of delivering 600mA Output Current over a wide input voltage range from 3.1 to 5.5V, the ASIC, that has a fixed operation frequency of 800kHz and 95% conversion efficiency, is ideally suited for portable electronic products. No external Schottky diode is required in practical application.

Research and design of a power management chip for wireless powering capsule endoscopy

This paper describes a power management chip for wireless powering capsule endoscopy, including over-voltage protection circuit RF limiter, CMOS rectifier and low dropout regulator (LDO). Bulk commutation technique is applied to suppress the substrate leakage current problem of CMOS rectifier. A bandgap circuit used as reference for LDO is optimized carefully and has a more than −50dB PSR at 2MHz, which can effectively suppress the ripple of rectifier output used as input voltage of LDO. It incorporates a voltage controlled current source (VCCS) compensation network to make sure the loop’s stability is not dependent on the output capacitor’s Equivalent Series Resistance (ESR). The proposed chip has implemented in 0.35μm CMOS technology and the measurement results show that it can provide as high as 63.8mA output current at a 3V output voltage. The PMC has been used in a wireless powering system designed for capsule endoscope application. Experiment results show that the Power Management Chip (PMC) can deliver as high as 191mW DC energy to the load, imitating the physical condition in a biomedical environment in a human body.

Semiconductors and Information Technologies

Semiconductors and Information Technologies

Microcontroller based Power Efficient Signal Conditioning Unit for Detection of a Single Gas using MEMS based Sensor

Abstract -A low power MEMS based sensor along with the embedded power efficient signal conditioning unit (Microcontroller based), which can be used with any suitable sensor-network to detect and quantify variations in a particular gas concentration, has been reported in this paper. The power consumption of the MEMS gas sensor is ~ 70mW to 100mW depending upon its operating temperature (150-250°C) and that of entire signal conditioning unit (consisting of low noise amplifier, switch, microcontroller and power management chip) is ~ 36mW in the ON state and only ~7.2μW in OFF state (sleep mode). The test gas in this particular case was methane for which sensor resistance varied from 100KΩ to 10KΩ. This hybrid sensor system is very much suitable for detecting a single gas with display of corresponding gas concentrations and subsequent alarming if the threshold limit is crossed.

Design of a Low Power, High Performance BICMOS Current-limiting Circuit for DC-DC Converter Application

A low power, high performance current-limiting circuit implemented in 0.6um BICMOS process, which has been successfully applied to the chip of high e-ciency, wide input voltage range DC-DC boost switch power management chip, is presented. The circuit as the core sub-block of the chip consists of current-limiting comparator, soft starting and slop compensation. The dynamic bias and slop compensation technology in current-limiting comparator is adopted to improve the performance and to reduce power consume. In this paper, the deign methodology and process of the circuit is analyzed in detail. The simulation and test results based HSPICE show: under the power supply of 3.3V, the circuit has the gain of 117dB and low quiescent current of 15UA. DOI: 10.2529/PIERS060817034009 With the rapid development of the integrated circuit technology, the requirement of low power consumption, small volume, low cost for portable and powered equipment such as MP3, PDA and digital camera can be satisfled impossibly, meanwhile, the new functions belonging to the \energy hunger and thirst type are increasing with day, so it is key issue in this fleld how to integrate these new functions in smaller volume and to prolong the service time of battery-operated equipments. At present, the switch-mode DC-DC converters have been widely used in power supply systems and are becoming a common building block in modern VLSI systems, which are taking place of LDO and will be the best solution because of its high e-ciency. Therefore, it is meaningful and better market prospect to research the power management IC of high e-ciency, low power. Figure 1 illustrates a simplifled boost dc-dc converter's functional block diagram. Its main function is to convert input dc voltage to higher output dc voltage with minimum power loss. The converter is composed of a power stage and feedback control circuits. VS is a battery voltage, which supplies input dc voltage, and is the boosted output dc voltage. The inductor L, diode D1, and capacitor C are ofi-chip components. Resistors R1 and R2 sense the output voltage and generate the scaled output voltage to the error amplifler. RLOAD is the load of the dc-dc converter.