STMicros extend digital-power choices with STNRGPF02

2nd July 2020

Alex Lynn

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STMicroelectronics is extending its range of digital power-supply controllers with the STNRGPF02 for two-channel interleaved boost-PFC topologies. Customers can easily configure the device using eDesignSuite software that also helps quickly complete the circuit design and select external components.

The STNRGPF02 brings the advantages of digital power to applications from 600W to 6kW, including greater flexibility and faster design cycles compared with typical analogue approaches. At the same time, system integration is greater than other digital solutions that require a separate DSP or microcontroller.

Typical applications for the STNRGPF02 include industrial motors, air conditioners, domestic and commercial appliances, cellular base-stations, telecom infrastructure, data center equipment, and uninterruptible power supplies (UPS).

The STNRGPF02 operates in continuous-conduction mode (CCM) at fixed frequency with average current-mode control. An optimised blend of analogue and digital control combines a hardware analogue Proportional-Integral (PI) compensator in the inner current loop and a digital PI controller in the outer voltage loop, ensuring fast response. Cascaded control for the voltage and current loops regulates the output voltage by acting on the total average inductor current.

Designed for mechanical inrush-current control using an external relay or triac, the new controller joins ST’s digital-power portfolio alongside the STNRGPF12 featured for digital inrush control with a solid-state device. Both controllers support programmable phase shedding, load feed forward, and burst mode to maximise energy efficiency. Built-in protection features include programmable fast-acting thermal and over-current protection (OCP), over-voltage protection (OVP), and soft-start management. PFC Fault and PFC OK status indicators are also provided.

The STNRGPF02 is easily configured using eDesignSuite by inputting the converter specifications and running the configurator. The tool generates a full schematic, Bill of Materials (BOM), and binary object code as firmware ready to download via the IC’s serial communication port, which greatly reduces the typical power-supply design cycle. The serial port also allows monitoring of the PFC parameters.

An evaluation board, STEVAL-IPFC02V1, is available to jump-start development with the STNRGPF02. The board contains a PFC reference design that combines analogue cycle-by-cycle current regulation with the flexibility of digital control to implement power supplies with very high-power factor and very low harmonic distortion.

The STNRGPF02 is in production now, packaged as a TSSOP38 device, from $2.67 for orders of 1,000 pieces.