Discussion on the management trend of the hottest

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Discussion on the trend of power management

with the development of semiconductor terminal products towards the three major trends of lightweight, short, digital and integrated multi-function, the status of power management IC in the analog field is becoming more and more important, and its achievements are also very bright. Under the prosperity of the market, the design trend of power management is also worth paying attention to, The leading power management chip suppliers in the industry have expounded some of their technical views and corresponding solutions from different levels

white LED drive has become the focus of design

portable products provide backlight for LCD display. The light source that consumes the most power in the system, and its power consumption is more than ten times that of the display. The higher the power of the backlight, the stronger the light that can be emitted by the LCD of portable devices. Due to the increasingly stringent power limit, we cannot blindly pursue high brightness output. Therefore, white LED with low power consumption is still the most popular choice

at present, many manufacturers are developing white LED drive circuits with more compact structure and higher backlight efficiency. Peter Henry, vice president of portable system power management products of National Semiconductor Corporation, pointed out that as mobile continues to develop in the direction of multifunctional intelligence, the demand for LED drivers is expected to continue to increase. For example, at present, ordinary mobile devices generally only use 2 to 4 LED drivers. However, dual screen photography with more functions requires 7 to 9 LED drivers to meet the lighting requirements

ns' newly launched lp3936 lamp management unit has three groups of drives that can be controlled independently. One group is the main driver, which is responsible for driving four type 3 samples with a thickness of 1.0 ± 0.1mm) and the gauge distance at fracture is generally within 1 meter; LED of special thickness sample, mainly providing backlight for display with size no more than 2.5 inches; The other group is the auxiliary driver, which is responsible for driving two light-emitting diodes, mainly providing backlight for the sub display or keypad; There is also a group of LED drivers responsible for providing decorative lights or flash lamps

in addition, the application of a new generation of OLED displays in portable devices is also gradually heating up, and power IC suppliers are working hard to expand white LED drivers in this regard. Lizijun, manager of power management product technology marketing department of Sipex company, said that the 2.2-inch full-color PMOLED has been mass produced and is gradually emerging in the market with a large increase in the demand for color screens. Because PMOLED has a lower entry threshold than AMOLED and has a rapid rise in today's market, Sipex has launched several sp6690/91 series driver chips for customers to choose from

generally speaking, pmoleds require different driving voltages according to the size of the screen. For example, the voltage required for 1-inch full-color PMOLED is about + 11V. In application, since the standard voltage of lithium battery is between + 2.7V and + 4.2V, a boost IC is needed for voltage conversion to drive this kind of OLED

as for AMOLED, the technical threshold is high, so it is not easy to design a driving IC that meets the characteristics and enables the panel image to be evenly presented. Coupled with the competition for mainstream TFT LCD panels with stable yield and continuous decline in price, the future market prospect is not clear

lcd TV brings new demand

with the further decline of LCD panel cost and the further improvement of its performance, another emerging application of LCD - LCD TV has also entered the home, and the market demand is steadily rising. LCD TV manufacturers are increasingly relying on innovation in the field of power management as a key factor to differentiate themselves in the market

Steve mappus, application engineer of TI's system power management business, said that LCDTV is highly dependent on power management and requires circuits such as AC power factor correction, isolated power conversion, non isolated load point power conversion, and various levels of power monitoring, sequencing, monitoring and protection. For the current LCD TV design, traditional analog power control ICs and microcontrollers with one or more monitoring functions are needed

ti has a perfect layout of power products in this field. 300W to 400W power systems (most 40 inch LCD TVs belong to this kind of system) use switching power factor correction controllers (such as ucc28050/1) to increase the AC line voltage, so that it can reach a very high voltage DC output after adjustment. If the active clamp PWM controller (such as ucc2894) is then added, the overall efficiency of the LCD TV power supply system can be optimized, because a series of well-defined functions realize zero current switching for the power factor correction stage and zero voltage switching for the isolated dc/dc stage. For low-voltage non insulated load point conversion, Ti has introduced various dc/dc converters with integrated MOSFET, such as TI's swift dc/dc series or tps6xxx series low-voltage converters

specifically for the development of CNC power supply system, Ti recently launched ucd7k, ucd8k and ucd9k series fusion digital power digital power products, whose functions are equivalent to the sum of several high-speed analog control ICs. The microcontroller and LCD backlight display drive signals are unified into the same DSP based controller. As the requirements of LCD TV for power management become increasingly complex, digital power solutions will become more attractive in the future. However, Steve mappus also pointed out that the popularity of digital power supply in LCD TVs will depend on the close cooperation between LCD TV manufacturers and power management semiconductor manufacturers. As for the digital power supply itself, because a single scale cannot be suitable for all types of equipment, the promotion of digital power supply will depend on whether all parties can fully understand each other's specific needs

tends to be highly integrated

the development trend of power management technology is to integrate more functional features on smaller silicon chips, while achieving stronger system power performance with higher design flexibility without increasing costs. Li Qian, general manager of NS China, stressed that this is especially true for portable applications with very limited board space. The method of combining multiple single function power management devices will gradually become infeasible and may be replaced by chips similar to PMU (power management unit)

for example, the NS multi-functional power management unit lp3970 has built-in 11 low-voltage noise reducing linear regulators, of which 8 are responsible for driving digital loads, while the other 3 are responsible for driving analog loads. Lp3970 also has 2 inductive dc/dc step-down regulators, 1 backup battery charger and 4 general-purpose outputs, which can provide regulated power supply for application processors. Through the I 2C interface, the application processor can digitally control the lp3970 and dynamically adjust the power supply voltage according to the load condition to save power consumption

Maxim company launched max8621y/max8621z power management IC, which integrates two step-down dc/dc converters, four LDOS, a reset timer and a driver, with a footprint of only 16mm2. If seven discrete SOT23 packaged components are used to achieve the same function, 75mm2 of circuit board area is required

it is imperative to reduce energy consumption

in order to meet the requirements of the high rigidity host machine produced by the microcomputer screen hydraulic universal experimental machine produced by Jinan new era Gold Testing Instrument Co., Ltd., which is energy-saving and environmental friendly, many governments and energy institutions around the world have also issued various new energy consumption standards for different applications and different power consumption ranges. At the same time, stricter norms are also being formulated. Reducing energy consumption has become an important issue that cannot be avoided. At the same time, it also puts forward higher requirements for power management

it is encouraging that there are many new products that can play a role in reducing energy consumption. Taehoon Kim, vice president of high-power products Department of Fairchild Semiconductor Company, said that the energy consumption of household appliances usually accounts for about 20% of the total energy consumption, and the reduction of electricity is the main source of energy consumption of household appliances. In the low-power home appliance market, high-voltage brushless DC motor (BLDC) is replacing single phase AC motor, which not only improves the efficiency from less than 50% to 90%, but also reduces the noise and vibration that can be heard by human ears

generally, white appliance motors with power less than 100W need to use discrete MOSFET transistors and half bridge integrated circuits, as well as noise filtering components, which have large space occupation area and have no advantages in reliability and cost. Fairchild Semiconductor has developed a more effective intelligent power module (SPM), among which the just launched intelligent motion power module (motion SPM) (fsb50325fsb50250h and fsb50450) are multi chip modules, including six fast recovery MOSFET transistors (frfets) and three half bridge high voltage integrated circuits (hvics). For BLDC motors in white appliances, this module can save 60% of the energy consumption cost

for switching mode power supply, it is very important to reduce standby energy consumption. Ansenmey semiconductor has made a lot of efforts in this regard in recent years. Yu Hui, the company's senior market application engineer, said that the vast majority of ansenmey's PWM control chips have standby functions. The chip itself can realize the standby function by detecting the working state of the circuit and forming different angles from each seal under no-load or light load. In order to further reduce the standby energy consumption, from the perspective of system design, Ansenmei also launched a PWM control chip ncp1230/1 with extremely low standby energy consumption. This series of products can turn off power factor correction (PFC) at light load/no load, eliminating a power link and reducing the standby energy consumption of the whole system. This product is suitable for adapter power supplies such as notebook computers and monitors

it is particularly worth mentioning that ncp1603, a high-efficiency, ultra-low standby power supply scheme with PFC level for adapters, was launched in the first quarter of this year. The chip has built-in discontinuous current type PFC control chip ncp1601 and current type PWM control chip ncp1230. It integrates PFC and PWM chips into one, fully combines the advantages of the two chips, avoids the common frequency synchronization problem of the two-stage design, and turns off the PFC section under light load/no load, realizing ultra-low standby energy consumption. (end)

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