A new single-phase point of load reference design promises to help engineers to easily and quickly implement digitally-controlled POLs for many end applications including servers, telecom, datacomm and storage systems, medical equipment and aeronautical systems. The reference design is a 20A POL suitable for packaging as a stand-alone power supply module or implemented directly on the end application circuit board by the OEM. Included in the reference design is a pre-configured software kernel that features active dynamic dead time control for maximum operating efficiency, non-linear control response for fast transient response, and an SMBus port capable of supporting industry-standard communication protocols.

The reference design kit is shipped with a complete development tool suite enabling users to modify the POL application code as desired. This tool suite consists of a GUI-based application builder that initializes the switch timing, loop compensation filter and processor set-up without the need for writing application software. Also included is an Integrated Development Environment that contains an editor, macro assembler, demo C compiler and a special online debugger. The latter gives the user the ability to do manual inspection and adjustment of system parameters during power supply operation.

The kit includes full schematics and layout (Gerber) files for fast time to market. The total area occupied by the POL is only 615 mm2. It delivers a maximum of 20A for a complete 20A/100W power converter. The reference design utilizes a 4-layer PCB and is available with all necessary connectors and switches for complete evaluation of the product. Also included is a USB debug adapter, USB to SMBus communications adapter, USB cable and 2O load resistor.

The POL reference design (P/N SINGLEPHSPOL-RD) is based on the Si8252 digital power controller in a 32-pin QFP package and is available now for $149. SILICON LABORATORIES, Austin, TX. (877) 444-3032.

Key Component
Si8252 Digital Power Controller

A member of the company's Si825x family of programmable digital power controllers, the Si8252 provides closed-loop feedback control, system protection and power management functions for switch mode power systems. The Si825x architecture combines a dedicated DSP-based control loop processor with an in-system programmable system management processor. This architecture guarantees the control loop is updated at 10 MHz, regardless of firmware size and complexity for the fastest possible control response. Firmware can change all control parameters on the fly (loop gain, compensation, timing, etc.) enabling the system to quickly and intelligently adapt to changing operating conditions, such as loading and unloading transients.

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