New Industry Products

Smart Off-Line Converter IC with Zero-Power Standby

October 26, 2015 by Jeff Shepard

The reign of dreaded "vampire power" could be about to end thanks to the latest power-supply chip from STMicroelectronics. The new IC meets the international specification for zero standby power, and is the first in the world to provide a smart way of managing the wake-up function in appliances such as white goods, in lighting, and in industrial equipment. Thanks to its unique smart architecture, the new VIPer0P is able to provide standby power for the system host microcontroller while in idle mode. This allows the system to be woken via the main-appliance user interface, such as the touchscreen or a remote controller.

There is no need for a dedicated high-voltage mechanical switch to take the appliance out of standby. VIPer0P consumes less than 5mW in idle mode (at 230Vac supply). This best-in-class performance is rounded to zero power according to Clause 4.5 of the IEC 62301 standard for household and office appliances. If a switch is used to control standby, idle power can be further reduced to 4mW. Switching can be done at SELV, hence eliminating bulky high-voltage components.

VIPer0P is an off-line power-converter IC that can be configured as a flyback, buck, or buck-boost switched-mode power supply. As the latest member of ST’s high-voltage VIPerPlus series, it integrates an avalanche-rugged Power MOSFET with class-leading breakdown voltage of 800V thereby giving designers greater safety margin to ensure superior reliability. VIPer0P also has comprehensive protection features including short-circuit protection, Vcc clamping, thermal shutdown, and soft-start. The oscillator controlling the switching frequency is jittered to minimize electromagnetic interference.

Additional features include integrated high-voltage startup circuitry, error amplifier with 1.2V reference and separate ground for direct feedback connection, and a sense-FET for energy-efficient current sensing. These simplify design and minimize external components thereby saving bill-of-materials costs and board space. In addition, VIPer0P’s self-supply design simplifies transformer selection by eliminating any need for an auxiliary winding.

The long-running battle to minimize power sucked in by equipment in standby mode (vampire power) has driven worldwide adoption of proposals such as the IEA initiatives to reduce standby power used by appliances to less than 1W in 2010 and 0.5W in 2013. Today, the most advanced power-supply technologies are capable of driving down standby power consumption below 5mW, which is rounded to zero according to the IEC standard for household and office appliances.

Although regulations are driving down standby power per appliance, the number of appliances in use globally is increasing. ST’s new VIPer0P IC helps reduce wasted power and CO2 emissions by enabling effective zero-power standby in appliances such as clothes dryers, washing machines, dishwashers, coffee makers, and microwaves. The chip can also be used in lighting controls, industrial appliances, and air conditioners. By introducing a unique, patented smart-management capability not offered by any other converter in the market, VIPer0P allows the appliance to be woken from standby via a touchscreen or remote control thereby enhancing convenience for users.

“Designers at the world’s leading appliance brands rely on our VIPer® avalanche- rugged integrated Power ICs to meet the toughest eco-design specifications,” said Matteo Lo Presti, Group Vice President, Industrial & Power Conversion Division, STMicroelectronics. “VIPer0P now adds advanced zero-power technology to the superior ease of design, energy efficiency, and ruggedness that characterize the VIPer family.”

VIPer0P has been designed into forthcoming new appliances by lead customers, and is now in volume production in the SO16N surface-mount package, priced from $0.54 for orders of 1000 pieces.