Unlike portable electronic products that used disposable dry batteries or alkaline batteries as power sources, today, whether it is laptops, mobile phones or MP3/MP4 players, rechargeable batteries such as lithium ion, nickel cadmium or nickel hydride are basically used. The cost of use is good for the environment, and more importantly, the battery capacity can be made larger to get longer battery life. Rechargeable batteries also impose new requirements on system developers due to their own characteristics. In order to make rechargeable batteries have a longer service life, proper charging circuit design and device selection are essential, whether it is an external charger or system. Internal charging power management solutions need to be carefully considered based on specific usage.
This article refers to the address: http://
Single-chip charge management solution will become mainstream
In portable products, battery charging can usually be done in two ways. One is to use the system's own master MCU plus a pulse width modulation and demodulation unit (PWM), and the other is to use a highly integrated single-chip charge management IC. . "The biggest advantage of the single-chip charge management IC is that it has higher reliability, and the MCU+PWM solution is cheaper and simpler." Wang Yun, manager of Fujitsu's microelectronics marketing department, explained in an interview with this reporter, "System Manufacturing The quotient can compare the advantages and disadvantages of the two schemes in terms of cost and reliability, and select the most suitable scheme. In the long run, with the cost reduction of the single-chip charging management IC and the increase of external communication functions, more The choice of a more reliable single chip will be a trend."
According to Wang Yun, Fujitsu's charging management products are mainly located in the market above 2Cell, and the largest market for 2~4Cell applications is a notebook computer. Since 15 years ago, Fujitsu Power Management's R&D team has worked with Fujitsu's notebook R&D department to develop a charge management IC for notebook computers. Through the continuous development and improvement of several generations of products, the newly developed lithium battery charging management ICs MB39A132 and MB39A134 have been applied in many large factories in Taiwan and mainland China, and are also receiving attention from the recently high-profile netbook market. "In notebook applications, due to the explosion of rechargeable batteries in the past few years, the notebook designers have paid more attention to the design of the charging part. In the charging management part, the brand management with high quality and high reliability is selected. IC," he said.
However, Dr. Wu Wei, AC/DC product director from BCD Semiconductor, is more optimistic about the MCU+PWM solution. He believes that the control scheme circuit formed by the dedicated charge management IC is simple but has a single function, usually only for lithium-ion batteries with specific parameters. Charging, and different types of portable products often use different types of lithium-ion batteries, if using a dedicated chip, it will cause repeated development and waste of resources.
"The Buck circuit realized by MCU+PWM has low cost and flexible control method, and can be easily improved and upgraded, and can be applied to various lithium ion batteries," Wu said.
BCD Semiconductor is an analog signal IC manufacturer (IDM) based in Greater China, specializing in the design, development and manufacturing of power management IC products. Unlike other Fabless design companies on the market, BCD Semiconductor has a 6-inch fab
(including Bipolar, CMOS, BiCMOS and BCDMOS production processes), product design and advanced process technology integration to optimize product performance and cost to provide cost-effective application system solutions.
In fact, BCD Semiconductor's focus is on high-efficiency, low-cost AC/DC off-line power adapter/charger control chips. The first generation of primary-side controller AP370x series developed by the company in 2006 is the first product of its kind on the market. one. According to reports, AP370x adopts the patented technology of primary side control and output cable compensation, built-in temperature compensation and transformer primary inductance compensation, which can realize high-precision output voltage and current control without the need of optocoupler and secondary feedback control circuit. This greatly reduces the number of components in the power supply circuit and simplifies the circuit design. It has been successfully applied to chargers/adapters for mobile phones, wireless public telephones, cordless phones, and wireless routers. "In order to further improve the power conversion efficiency and reduce the standby power consumption, we have further introduced the second generation primary side controller AP376x series that meets the five-star standard in the industry. The no-load power consumption below 30mW can easily meet the energy consumption. All the chargers/adapters in the world, including EPS v2.0 and five-star mobile phone chargers, have energy efficiency and no-load specifications." Wu Hao said.
Input power is increasingly diverse
With the increasing diversification of people's living environment, the power supply for battery charging is also increasingly diversified. In addition to the traditional 220V AC adapter, users also want to be able to charge the battery of various devices at any time through the USB interface or vehicle power supply. In addition, users are required to continue to use their functions while charging, so the device's charge management circuit needs to be more flexible to adapt to a wider range of applications.
Obviously, the new requirements also pose greater challenges for system manufacturers. “The challenge comes first from the fact that the charge management IC requires a wider operating voltage range, which requires the use of higher voltage semiconductor processes for chip design.†Wang Yun said, “The second challenge is to require ICs to have different inputs. The power supply is adjusted accordingly, and the battery is charged and the system uses some power to manage it.†He explained the Fujitsu MB39A132/134 charge management IC as an example. By dynamically allocating the input current, the system is powered. Charging with the battery can be carried out at the same time.
Since the voltage and current supplied by the AC adapter/USB/vehicle power supply are different, and the voltage and the number of sections of the rechargeable battery are not the same, when the charging voltage is higher than the power supply voltage, the voltage can be charged by boosting. The charge management IC has not been seen in the market. In addition, when the device is working at the same time, the charging management IC is required to have a good anti-interference design. At the same time, it should be noted that in the case of a very low battery voltage, the charging current must be greater than the discharge current to avoid the situation of "not getting enough". "From the perspective of the design of charging ICs, the current challenges include: 1. How to further improve the charging conversion efficiency and reduce the power consumption of standby; 2. How to effectively manage the power and load of multiple channels; 3. How to increase the charging rate and simultaneously To ensure the safe service life of the battery; 4, how to further expand the flexible configuration of the charging control method in order to adapt to the charging requirements of different types of batteries." Wu Hao added.
He believes that portable product chargers such as mobile phone chargers are a relatively mature and stable market. At present, most domestic manufacturers are mainly manufacturing, and the power of technology development is relatively weak. At the same time, the charger itself is a small profit product, the manufacturer's cost control pressure is relatively large, and the acceptance of new technology is relatively low. In recent years, due to the increasing public awareness of environmental protection, the government and various environmental organizations and organizations, including mobile phone manufacturers themselves, have proposed a number of energy-saving and environmental protection standards related to chargers, such as the mobile communication handset charger issued by the Ministry of Industry and Information Technology of China. Interface technical requirements and test methods (YD/T1591-2006), ENERGY STAR EPS2.0, mobile phone charger grading standards, etc., all aim to reduce resource waste, improve power efficiency, and reduce no-load air consumption. The introduction of these standards has greatly promoted the technological innovation of charger products.
“The main difficulty faced by Chinese manufacturers is that designers have not enough technical practice on charging to fully grasp the requirements of charging design.†Wang Yun said, “At the same time, the functions of various charging management ICs are different, users are new to The lack of understanding of the product, the design is not easy to get started. The solution mainly relies on the manufacturers of charging management ICs to increase the promotion of products and technologies to the market, and provide designers with multi-faceted technical support, so that designers can quickly grasp the design of charging management. technology."
In the notebook design, engineers pay great attention to the design of the charge management IC. Otherwise, if the problem will cost the engineer a lot of time and energy, it is very important to find the problem early in the research and development. Wang Yun said that in addition to providing evaluation boards for customer system evaluation, Fujitsu has also developed a notebook power supply design evaluation system. Through this system, customers can provide complete pre-examination of any problems that may occur as long as they provide complete circuits. Thereby helping to reduce the risk of research and development.
The global financial tsunami that occurred in the second half of last year has dealt a huge blow to consumer electronics. "But we are pleased to find that consumer electronics has begun to recover from the overall economy. In particular, benefit from the national subsidies for home appliances to the countryside, laptops and LCD TVs. Wait for the market to pick up quickly." Wang Yun said. "Next year, we will continue to increase investment in power management IC research and development, and will launch a new generation of charging management products. In recent years, new energy technologies have been continuously developed, battery technology has attracted attention, and lithium batteries/lithium batteries will also be It is applied to more products. From the perspective of power management ICs, safer, higher precision, multiple protection functions, external communication functions, battery balance charge and discharge functions, and multiple battery wide voltage inputs will become battery charge management. The future of technology."
New type AC Contactor, our model is BC1-D series. New AC Contactor is the new designed AC Contactors, which with a new face appear to the user with high quality product. This product uses the fresh PA66 nylon material, no any recycled material mixed. Have high protection level for the fire-resistant. White body, yellow inserting core, looks more charming. All the metallic parts are standards of quality control.
The AC Contactor is suitable for using in the circuits up to the rated voltage 660VAC 50Hz or 60Hz, rated current up to 95A, for making and breaking and frequently start, controlling the AC motor. Combined with the auxiliary contactor group, air delayer, machine interlocking devices etc. It is combined into the delay contactor, mechanical interlocking contactor, star-delta starter, with the Thermal Relay, it is combined into the electromagnetic starter.
New AC Contactor
AC Contactor,Magnetic AC Contactor,ACMagnetic Electric Contactor,Electrical Power AC Contactor
Ningbo Bond Industrial Electric Co., Ltd. , https://www.bondelectro.com