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GGE Corp., Limited
2 Floor, B6 Building, 2nd Industrial district, Shi'ao, Langqin Road, Dalang, Longhua, Bao'an District, Shenzhen 518109 China
Tel:+86-755-88257880
Fax:+86-755-88257891
CEP: +86-13244899899
CP: Ms Megan Deng
E-mail: sales@chinagge.com
www.chinagge.com
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| New efficient and compact white LED driver program |
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Without increasing costs, exterior components and published circuit board space, new whitened led driver topologies will have the ability to produce industry-leading effectiveness and simple structure within the charge pump.
System designers are facing a formidable challenge, they need to use hue easily transportable showcase necessary to increase process features and effectiveness while also attaining charge and dimension within the smallest. The time has seem the decision for process designers to produce a new led driver topologies time.
White led takes about 3.6 V provide voltage to obtain the right brightness control. However, most handheld devices use lithium-ion electric battery for power, they are about 4.2 volts after completely charged, after the protection is done and power is all about 2.8 volts, obvious whitened led could not be directly driven covering the battery. Alternative option must be to use a boosted circuit when needed increase producing the voltage to use within the week during the entire electric battery for the led steady uninterrupted power supply.
LCD showcase employed within the led driver has two requirements. initial of all, they handle also to have got the ability to accurately complement the brightness of every LED, which will increase the consistency of keeping the showcase backlight; second led push you need to have got the ability to input the electric battery voltage increases, this tends to ensure using the entire cell period in led can provide enough push voltage, thus extending gear lifetime.
Inductor-based led driver is mostly accustomed to push series-type connection LED, this structure alone can provide identical match. They also provide varying and optimize the proportion of voltage increase, so attributes a highly high power transformation efficiency. However, credited to your dimension and charge of exterior components, as accurately as irritating electromagnetic interference (EMI), inductor-based led driver program has evident flaws. Bulky inductors restrict this program within the slender and minimal look of small handheld devices.
On the other hand, charge pump-based led driver gives a highly good solution, the exterior circuit can only use a highly small capacitance. Which makes even more growth in usage is smaller and slimmer easily transportable devices a great choice. Charge pump latest on each channel using the matching of latest impartial push the parallel connection within the LED, however, is a discrete step-up ratio, the various modes of operation (multiplication factor) may be. the amount of available running modes and latest electric battery voltage determines the charge pump power efficiency.
Common charge pump scheme utilizes two exterior flying capacitor to produce three running modes (1-fold, 1.5 fold, a few of fold) to carry out boost. With the electric battery consumption, the devices boost parameter successive increase. In each step-up model, the greatest level of output voltage identical to input the electric battery voltage by multiplication factor. Over-driven led voltage necessary part within the energy, or within the charge pump latest regulator have been consumed, which minimizes the circuitĄ¯s transformation efficiency.
Embed significantly more lithium electric battery running mode helps to restrict the entire existence period within the high voltage gain, thus enhancing efficiency. Some within the charge pump latest to produce a fourth running mode (1.33 times), according to just one times, 1.33 times, 1.5 periods and a few of periods in change increase the output voltage. 1.33-fold boost to obtain the conventional techniques need to improve the device pins and the amount of exterior components, accordingly, significantly more pin package and larger areas of published circuit board space, making the option charge is much greater than only three types of operation mode within the device.
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