Controllers Take On Complex Power Systems

Oct 1, 2006 12:00 PM
By David Morrison, Editor, Power Electronics Technology

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Point-of-load (POL) power applications continue to inspire the development of more sophisticated power controllers with greater ability to manage power distribution and enhanced power conversion performance. In terms of the first criteria — power management — digital power controllers are making great strides by integrating the power-supply sequencing, monitoring and fault-protection functions that previously required many external components. And as one recently announced IC from Texas Instruments (TI) demonstrates, digital controllers can also allow one chip to perform the pulse width modulation (PWM) control function for multiple channels of dc-dc conversion.

Meanwhile, analog power controllers are achieving greater accuracy and faster transient response to suit the stringent demands of CPU advance in areas where analog has always had advantages. Specifically, analog core power applications. A new power controller from Intersil demonstrates such gains, while also illustrating the influence of Intel's dual core CPUs on controller development.

Exploiting DSPs

TI's just released TMS320F28044 digital signal controller exploits the computing power of a 32-bit digital signal processor with 100 MIPS of performance to manage up to 16 dc-dc converter channels using a single device. The controller targets the type of multichannel POL applications found in telecommunications and networking infrastructure equipment, servers, laptop computers and industrial equipment. At only $5 in volume, the F28044 device provides full digital loop control and system management for as little as $0.32 per channel.

The F28044 implements up to 16 channels of TI's high-resolution (HR) PWM technology, each with 150-ps resolution, and is based on the fully programmable TMS320C28x 32-bit DSP core. Also integrated into the F28044 device are a high-speed 12-bit A-D converter, 128 kbytes of flash memory, and multiple communications ports with support for the PMBus interface (see the figure).

The programmability of the F28044 controller allows designers to build intelligence into power-supply systems and simultaneously manage in real time the sequencing, margining, phase compensation and transient response of multiple dc-dc converters. The combined performance of the F28044 controller and the integrated HRPWM channels provide the full digital loop control and output accuracy necessary at switching frequencies over 1 MHz.

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