Taiwan Chang Yang Technology launched - modified high pressure non isolated LED driver SQ9910

In LED lighting applications, non isolated driving (non-isolation) IC has played an important role in this kind of product structure, compared to the isolated type has higher efficiency, smaller space and plate, and system cost is low, so in many applications and in the field, has gradually become the mainstream scheme. SQ9910 continuation of the previous similar industry product specifications, including the input voltage wide (85-265VAC), simple constant (constant current) the basic characteristics of design, also increased over temperature protection (Over Temperature Protection), surge current control, constant current output than other brands more stable, double drive voltage selection MOSFET (7.5V/10V), output level compensation function, integration in a chip, is the same level of the chip specification is the perfect solution SQ9910 can be as high as 300kHz frequency with fixed frequency mode (fixed frequency mode), or fixed off time mode (constant OFF-time mode) to operate, to effectively reduce the noise. EMI SQ9910 used a unique high-pressure process design, and special similar built-in soft start therefore, Can withstand up to 500V surge input voltage impact. Design of power supply in LED lights this characteristic, can be avoided because of different countries in the world, the three-phase power surge voltage may cause damage to the tube and MOSFET system. To reduce switching losses, SQ9910 for non isolation scheme previously on the market, such as HV9910 deficiency, made an improvement. For example, this type of IC MOSFET driving voltage mostly only 7.5V, in general, domestic high voltage MOSFET tube, in 7.5V gate voltage VGS, cannot fully on MOSFET tube, therefore, SQ9910 same architecture based on the Chang Yang technology push out the driving voltage in A the version of the program 10-12V (SQ9910A). Without changing the original PCB design case, it can be obtained by increasing the driving voltage of the MOSFET tube further conduction and the system conversion efficiency, thus reducing the MOSFET tube temperature. In addition, dimming SQ9910 and industry the same level chip provided by the same way, with linear dimming (linear dimming) and pulse modulation (PWM) in two ways, can adjust the duty ratio of precise dimming effect reached 0-100%. Recently advanced countries in the LED lighting energy saving application specification and requirements for higher power factor. In non isolated this kind of scheme, due to the limited space chip itself and the system generally adopts the passive relatively low cost (passive) valley line (valley-fill) to improve the power factor (PFC). The main function is circuit by using high voltage electrolytic capacitor the conduction angle becomes larger in the input, to improve the power factor by the harmonic distortion, and improve the power factor of the objective. But because of the line, capacitor is connected in series structure, so rectified DC input voltage, after filling valley line, will be reduced to half of the input voltage at the output, caused by Current Mode Buck Converter in system design (Current Mode Buck Converter) on duty is more than 50%, when is the output voltage is greater than half of the input voltage, will dimensional harmonic oscillation (sub-harmonics oscillation) generated noise caused by magnetic assembly. SQ9910 using automatic frequency removing way, eliminate the noise in this class. In the next six months, Chang Yang technology will continue to launch innovative features (features) a series of and SQ9910 pin compatible chip to meet the more high-end LED power system requirements. General, power module LED lighting using a constant current, at no-load without proper protection circuit, will produce the phenomenon of machine explosion, so sold on the market in the power supply module, are to emphasize the need to add LED load, you can turn on the power switch. SQ9912 is the first to have open circuit protection (Open Loop Protection) circuit in IC chip LED driver. Chang Yang technology company is currently available only with the protection mechanism of solution. This particular design is currently in patent applications. In addition LED, due to the characteristics of the light source, generally after aging for a period of time, LED is likely to cause damage, causing the system circuit breaker, so LED power system protection at the output is required, SQ9912 open circuit protection is able to overcome the danger because of circuit breaker caused by no-load bombing. In addition, separation of LED lighting another trend in energy-saving environmental protection is light and electronic systems, because LED itself is a solid state component (Solid State Device), long life (typical value is 30000 hours), but electronic parts of the life, especially the electrolytic capacitors, far low to thousands of hours of (typical in 5000 hours), in a period of time after aging, can replace the electronic part through to prolong the service life of the whole in this. Under the trend, the light source and the power module is two subsystems separated, if the system design without protection device and preventive measures, installation process is likely to occur the bombing.