STMicroelectronics – New chip clamps down on vampire power in appliances, lighting and industrial equipment


ST’s VIPer0P: supports flyback, buck and buck-boost topologies

The phenomenon of ‘vampire power’ – the energy used by equipment which is standing idle – could be about to end thanks to the latest power-supply chip from STMicroelectronics.

The new VIPer0P AC-DC power converter from ST can drive down stand-by power consumption to 5mW while fed by a 230V AC supply. This is rounded to zero according to the IEC 62301 standard for household and office appliances.

The converter is also the first in the world to provide a smart way of managing the wake-up function. In the VIPer0P, ST has introduced a patented smart-management capability not offered by any other converter in the market: because it is able to provide stand-by power for the host microcontroller while in Idle mode, the system may be woken via the main appliance’s user interface, such as a touchscreen or remote control. This means that there is no need for a dedicated high-voltage mechanical switch to take the appliance out of Stand-by mode.

If a switch is used to control stand-by operation, Idle power can be reduced even more, to 4mW. Switching can be performed at Safety Extra-Low Voltage (SELV) levels, eliminating the need for bulky high-voltage components.

VIPer0P may be configured as a flyback, buck, or buck-boost switched-mode power supply. It integrates an avalanche-rugged power MOSFET with a breakdown voltage of 800V, giving designers a high safety margin for superior reliability.

Other features include integrated high-voltage start-up circuitry, and a sense-FET for energy-efficient current sensing. In addition, VIPer0P’s self-supply design simplifies transformer selection by eliminating the need for an auxiliary winding.


  • Current-mode PWM controller
  • Over-current protection
  • Jittered switching frequency reduces EMI filter cost
  • Embedded error amplifier with 1.2V reference
  • Pulse-skip protection to prevent flux runaway
  • Embedded thermal shut-down


  • Home appliances
  • Home automation
  • Industrial equipment
  • Lighting
  • Consumer devices


This evaluation kit demonstrates a 7W dual-output (7V/-5V) flyback converter with a non-isolated topology, based on the VIPer0P off-line converter IC.
Orderable Part Number: STEVAL-ISA174V1