Controller simplifies access to digital-power advantages

In high-power applications above 1 or 2 kW, interleaved CCM PFC (Continuous-Current Mode, Power-Factor Correction) topologies are mandatory to handle such power levels with reasonable magnetic volume and current split. Moreover, the quest for higher efficiency, connectivity, and configuration options encourages the use of expensive and complex DSP solutions.

ST’s new SMPS controller for interleaved boost-PFC topologies is configured quickly and easily using ST’s eDesignSuite online design environment, and has I2C and UART interfaces for monitoring and control.

It supports three interleaved phases, which ensures low ripple currents, simplifies EMI-filter design using small-size inductors, and permits a wide power range from 500W to over 20kW. Moreover, the STNRGPF01’s flexible, configurable phase-shedding strategy optimises the number of active phases automatically to maintain high efficiency across all load conditions.

The STNRGPF01 operates in CCM at fixed frequency with average-current-mode control. A hardware inner-current loop ensures accurate cycle-by-cycle regulation, while a digital proportional-integral (PI) controller manages the outer voltage loop to ensure fast dynamic response.

The frequency can be programmed from a few kHz to over 300kHz, to control either an IGBT or MOSFET output stage. Other configurable features include inrush-current limiting and PFC soft power-on.

By delivering the advantages of digital power through easy configuration in eDesignSuite, the STNRGPF01 enables superior flexibility, reliability, safety, and energy efficiency in equipment such as industrial welders, motor drives, pumps, uninterruptible power supplies (UPS), industrial or consumer air conditioners, and domestic appliances such as refrigerators, washers, dryers, and cookers.

ST’s design methodology enhances freedom to focus on the end application. Entering the converter specifications in eDesignSuite and running the configurator automatically generates the schematic, bill of materials (BoM), and downloadable firmware to configure the IC.

Designers can enjoy flexibility unmatched by analog controllers, without needing to understand processor memory and interrupt structures or write code to implement the required functions in a DSP. The STNRGPF01 is in full production, packaged as a TSSOP38, priced from $3.50 for orders of 1000 pieces.