Just as the wireless and cellular communications explosion is driving advances in semiconductor processes and RFICs, along with a host of other related technologies like antennas, packaging, thermal management, and embedded software to name a few, power management is also reaping the benefits of such progress. With every new generation of cellular handset or mobile phone, consumers are seeking additional features and functionalities with more talk time from a slim design without pinching the pocket. That means, semiconductor developers have to pack more on-chip, whether it is a RFIC, baseband processor or a power management solution.

In fact, power management is getting complex as a new handset today incorporates multiple technologies and, therefore, needs a variety of voltages to drive RF/microwave front-end circuits, mixed-signal converters, digital baseband chips, high-power analog amplifiers, and high-voltage peripherals. With the stringent requirements of system design, discrete power solutions are getting outdated and integrated power management chips are gaining momentum.

Take for example Dialog Semiconductor's power management chip introduced a few months ago. The chip includes 18 programmable LDO voltage regulators that create stable, low noise supply voltages for all other ICs in the handset, PDA or other portable electronics. Plus, it includes two high-efficiency dc-dc buck converters that provide high current, low-voltage supplies to the processor core and memory support with digitally controlled dynamic voltage management (DVM) and programmable voltage and slew rate control. A further boost converter generates a programmable high-voltage supply, up to 25 V and 1.3 A, which may then be used to power individual LED backlighting channels and high-power Flash or video light LEDs.

This CMOS-based integrated power management chip addresses the growing need to merge more functions so that battery life can be prolonged and smaller and thinner handheld solutions can be realized. According to Dialog Semiconductor, it is a system-on-a-chip (SoC) solution that reduces the component count as well as reduces PCB area by more than half. It is said to be the most highly integrated power and audio controller to support application processors in 90 nm technologies and below. The CMOS IC connects directly to the battery, providing complete control of all power management, battery charging, audio (stereo audio playback, microphone, loudspeaker and hands-free functions), white and general-purpose LED drivers, USB interface and many other functions that need to be controlled in a portable multimedia device.

Likewise, several other power semiconductor suppliers are addressing similar needs. Freescale Semiconductor, for instance, is meeting the needs of smart 3G phones with integrated power management and user interface (PMUI) chip that includes a full audio system, battery charger system, lighting system, five switching regulators, 18 linear regulators, USB transceiver, car kit interface, touchscreen interface and more. Besides offering multiple voltages, the smart power process-based PMUI also features dynamic voltage scaling, multimode operation of the switching regulators and user-off support with power-interruption recovery. This was reported in the Analog Feedback section of Power Electronics Technology magazine (see “Portable Power Management Inspires Mega Integration,” June 2006, p. 54).

Meanwhile, National Semiconductor, Semtech and Texas Instruments are also pushing the art of power integration on a single die. While TI has readied a single-chip solution for one cell-powered smart phones, portable media players and other systems like GPS and satellite radio, Semtech Corporation has crafted a family of power management ICs (PMICs) for cell phones and multifunction portable devices that feature nine ultralow dropout (ULDO) regulators capable of sourcing up to 300 mA from multiple inputs via an I²C serial interface.

In essence, integrated power management chips are offering numerous advantages. Aside from lowering component count and related cost with reduced real estate, they are also simplifying PCB design. Few components translate into less inventory and higher reliability.

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