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General market trends adapter

From the general market view, the power adapter is mainly reflected a number of important trends. First, work efficiency and standby (no load) higher energy requirements. This version for the external power supply specification will EPA2.0 November 1, 2008 came into effect. Desktop computer power supplies in the internal power supply, the "Energy Star" version 4.0 specification (EPA4.0) requests from the first stage of July 20, 2007 entered into force. The specifications desktop in 20%, 50% and 100% load conditions, the minimum energy efficiency of 80%. In addition, the updated version 5.0 ac adapter specification requirements will be the first stage of July 1, 2009 came into effect, will require the use of computers within the power of 50% efficiency under low load conditions up to 85% in 20% and 100 % load conditions, the minimum efficiency of 82%.
It is worth mentioning that the energy efficiency of future requirements will constantly improve and evolve. To notebook laptops AC / DC power adapter, for example, the industry energy consumption in idle mode higher than the level of about 300mW, while the future of no-load mode, 150mW power consumption may be targeted. Moreover, the requirements of the multi-output adapters may also be included among the TreadTang standard.
Power adapter market, another important trend is the customer needs to have a higher output power, smaller size of the adapter, which involves the use of new topologies. Using ON Semiconductor's NCP1605 Power Factor Correction (PFC) controller and the NCP1396 resonant mode controller can be used to design desktop adapter 200W or 300W adapter. Adapter from the laptop computers, its power requirements from 50W to 70W range has increased to more than 100W rating. In addition, such as Apple and Lenovo ThinkPadX300 MacBookAir such new ultra-portable notebook power adapter is also smaller and lighter.
In addition to these trends, the other noteworthy trend is that in the "Energy Star" for an external power supply on the formal specification 2.0 power factor (PF) to relax restrictions. In fact, the already implemented in Europe and Japan IEC61000-3-2 harmonic reduction standard, more than 75W power adapter applications need to PFC. Both currently on the market the traditional "power factor correction + pulse width modulation" (PFC + PWM) two-stage structure, there are these two merge into a single section of PFC architecture. Two-stage architecture is able to 115Vac and 230Vac are achieved under the conditions of the power factor of 0.9, and the mini laptop ripple dynamic response speed and better performance areas, but this structure is a resource-intensive design, will use more components, such as the control IC, inductor and MOSFET, etc., and may result in decreased energy efficiency mode; contrast, single-stage PFC architecture to another section of the PWM and PFC section together, reducing the control IC , inductor and MOSFET's were used to achieve energy efficiency improvement and significant cost reduction. Only, single-stage PFC architecture of the external power supply 230Vac test conditions, the power factor is usually greater than 0.8, from 0.9 in the limit there are many Juli, to achieve 0.9 power factor restriction requirements, needs some modifications to the circuit However, such changes will lose a few percentage points of energy efficiency.
Therefore, the external power supply for the "Energy Star" official version 2.0 specification, will limit the power factor required input power greater than 100W external power supply and 115Vac voltage test condition, while not as required 230Vac; designed for the same time to 115Vac and 230Vac work under the conditions of the power factor in terms of external power supply needed to meet 115Vac only under the conditions of testing requirements. Thus, a higher cost for power adapters, single-stage PFC will win to even greater momentum.