Next-generation portable power management solutions

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Next-generation portable power management solutions [Copy link]

Portable electronic products (such as mobile phones, PDAs, MP3 players, digital cameras, video recorders, etc.) are developing rapidly and changing with each passing day, becoming the mainstream products in the electronic market. The main features of portable electronic products are small size and battery power supply.

　　Figure 1 Portable entertainment system block diagram

　　Figure 2 Multi-power system

　　Figure 1 shows a block diagram of a portable entertainment system and a power management system, wherein the power management system provides multiple voltage/current power supplies for the processing unit, memory, peripheral interface, audio codec, audio power amplifier, keyboard, touch screen, color display, white LED and backlight of the portable entertainment system.

　　Power management for portable electronic products mainly includes power conversion (voltage regulation, control, interface) and battery management (charging control, capacity monitoring, battery power conversion).

　　Power management is divided into power management subsystem and battery management subsystem. The power management subsystem includes buck converter, buck/boost converter, boost converter, charge pump, low dropout regulator, power controller, etc.; the battery management subsystem includes battery chargers for batteries of different chemical compositions (lithium-ion, nickel-metal hydride, nickel-chromium and alkaline), lithium-ion protectors, battery monitors, etc. Specifically including:

　　In order to achieve product innovation and meet the rapidly growing market demand, designers of high-performance portable electronic products must adopt excellent power management solutions, select advanced power management products, solve complex power management and integration problems, and achieve excellent cost-effectiveness for the system. To this end, Dave Heacock, director of portable power management products at TI, introduced the power management technology and solutions for the new generation of portable electronic products.

　　Power supply design technology and process

　　Power supply design needs to consider low cost, fast time to market, small size, light weight, high integration, low noise, low power consumption and long battery life, the ability to handle batteries of different chemical compositions, and adapt to the development trend of DC/DC power conversion and more intelligent battery management requirements.

　　TI's innovative technologies and processes include: using drain-extended CMOS with high voltage capability and die-oriented DMOS to reduce the number of external components. Compared with the equivalent RDSON, LDMOS technology can reduce the size of transistors by 2/3; combining the required 0.35m or smaller form factor with logic and power in a low-cost manner, enabling dense digital logic to have high power processing capabilities; using embedded programmable non-volatile memory, enabling the fine-tuning E2 to improve performance flexibility, yield and cost, and flash memory to improve algorithms, performance and flexibility; using multi-metal/multi-layer, copper-plated processes to make chip size smaller, impedance lower (up to 50 times), and enable capacitor integration.

The use of advanced WSP , QFN/SON, and TSOT packaging makes the board space smaller, the heat dissipation performance better, and the noise lower, forming a system with better performance, smaller size, and more sophisticated appearance.

　　In addition, TI has developed advanced battery management/power management algorithms that enable shorter battery charging times, longer battery life, better capacity management, and more powerful functionality.

　　Power Management Solution Examples

　　Power management solutions for OLED displays

　　The global OLED display market is developing rapidly and is expected to reach $470 million this year and exceed $1 billion by 2006, growing at an annual growth rate of 58%. High-value OLED displays enable OEMs to produce thinner, lighter, and lower-power digital cameras and other portable electronic products. To this end, TI has launched the first OLED power conversion IC for portable display design-TPS65130. TPS65130 is a dual-channel DC/DC converter with an adjustable voltage output range of -12V~15V, 89% power efficiency, and 800mA switch current limit. Its power-saving analog can provide high efficiency at low loads and can directly provide power from a single lithium-ion battery, multiple nickel-metal hydride, nickel-chromium and alkaline batteries.

　　Negative voltage LDO ultra low noise regulator TPS723

　　The LDO linear regulator series has a negative voltage 200mA output, with an output noise of only 60mV (RMS), and can provide 65dB PSRR (power supply rejection ratio) at a frequency of 1KHz, with an adjustable output voltage of -10V~1.2V and a quiescent current of less than 2mA in switching mode. The TPS723xx LDO uses stable and reliable low-cost, small ceramic capacitors, with startup and noise reduction functions; using a high-precision voltage reference, the initial accuracy can reach 1%, while the overload, line and temperature variation range is only 2%. This high-precision, low-power LDO supports battery-powered noise-sensitive applications, such as CCD digital cameras, PDA displays, and noise-sensitive circuit applications with optical drivers, optical networks and video amplifiers.

　　Single-chip battery management IC

　　The TPS65010 integrates key power management devices into a single chip for single-cell lithium-ion systems. It uses the new 3307A12 manufacturing process to integrate major control building blocks, external components (such as switches and charging FETs, etc.) and battery management intelligence to more effectively manage the power of products such as high-performance, low-power processors. Compared with discrete solutions with similar functions, it reduces the board space used by three times. This intelligent power IC can meet all key power management requirements for single-cell lithium-ion or lithium-polymer battery-powered applications containing multiple power rails, as well as applications such as PDAs, smart phones, digital cameras, etc.

　　Multiple power supply solutions

　　Figure 2 shows a multiple power rail solution. This solution can provide multiple power supplies such as greater than 20VDC, greater than 2VDC, less than 2VDC, and greater than 250VAC.

　　This power system includes battery components, power multi-way conversion switches, chargers, charge pumps, boost converters, buck converters, LDOs and other units. It can provide a voltage of less than 2V for the mP/DSP core, a voltage of more than 2V for the mP/DSP I/O and memory, a voltage of more than 20V for white LED backlight and LCD bias/contrast, a voltage for LED backlight and general systems, and more than 250VAC for CCFL (cold cathode fluorescent tube) and backlight.

　　The power ICs used in this multi-power system include: step-up DC/DC converters TPS64200, TPS65100, TPS6102x, LDO TPS723x, chargers bqTINYTM, bqTINY11, fuel gauges bqJuniorTM, bq2084/bq29313, power switch converters TPS211X, etc.