High-voltage converter brings high efficiency to fly-back, buck, and buck-boost topologies

STMicroelectronics has introduced a high-voltage power converter that allows designers to build an ultra-low-consumption, simple, and cost-effective SMPS (Switched-Mode Power Supply) with a 5V output voltage. Particularly suited for low-power applications in home appliances, building, lighting, and motion control, as well as small industrial and consumer applications, the VIPER01 operates directly from a rectified mains supply and integrates an 800V avalanche-rugged Power MOSFET with PWM (Pulse-Width Modulation) current-mode control and multiple protection circuits. The converter is tailored to provide the auxiliary supply to microcontrollers in IoT devices that are permanently connected to the Internet or a local network.

The new device belongs to the VIPerPlus^TM family of high-voltage converters, now in its second generation, and exploits ST’s proprietary BCD (Bipolar-CMOS-DMOS) technology. BCD allows the integration in a single chip of a high-performance PWM controller with a high-voltage logic-level control transistor, protection and diagnostic circuitry, without significantly impacting the robustness and reliability of the power transistor.

The VIPER01 enables designers to meet the most stringent energy-saving standards^[1], as it has very low power consumption and switches automatically to pulse frequency modulation under light load conditions. It can be used in fly-back, buck, and buck-boost converter topologies, while the integrated high-voltage start-up, sense-FET, error amplifier, and oscillator with jitter allow a complete application to be designed with the minimum number of external components.

Key features of the VIPER01 include:

• 800 V avalanche-rugged Power MOSFET allowing ultra-wide V_AC input range;
• Embedded HV start-up and sense-FET;
• Current mode PWM controller;
• Drain current limit protection;
• Wide supply-voltage range from 4.5V to 30V;
• Self-supply option allows auxiliary winding or bias components to be removed;
• Jittered switching frequency reduces the EMI filter cost;
• Embedded error amplifier with 1.2V reference voltage;
• Protections with automatic restart include overload/short-circuit, line or output OVP, maximum duty cycle counter, V_CC clamp;
• Embedded thermal shutdown;
• Built-in soft-start for improved system reliability.

The VIPER01 comes with a set of tools including evaluation kits, application notes, and spice models to jumpstart more robust, safer, and cost-effective SMPS designs.

VIPER01 is available now in volume at a price of US$ 0.364 for 1,000 units.