RRW2111x/RRW221xx Primary-Side Regulation Flyback SiPs

The Renesas RRW21111 is a system‑in‑package (SiP) product that integrates a 700 V SuperGaN® FET with a high-performance digital AC/DC primary‑side regulation (PSR) flyback controller. Its configurable light‑load mode allows the design to be optimized for ultra‑low no‑load power consumption or fast transient response through a single external resistor. Operating in quasi‑resonant mode, the device delivers high efficiency at heavy loads while reducing external component count, simplifying EMI design, and lowering overall bill‑of‑materials cost.

PrimAccurate^™ primary‑side regulation eliminates the need for secondary‑side feedback components while maintaining excellent line and load regulation. The digital control architecture removes external loop‑compensation requirements and uses pulse‑by‑pulse waveform analysis to achieve a faster dynamic response than traditional solutions. A built‑in power‑limit function supports transformer optimization across universal offline input ranges, and the RRW21111 is typically used in applications around 65 W.

The device enables high average active efficiency and no‑load power consumption below 75 mW. Its soft‑start capability provides smooth startup into large capacitive loads at any output voltage, making it suitable for networking and monitor adapter applications.

The RRW21111 includes internal and external overvoltage protection, with the external path providing supplemental output OVP for enhanced system robustness.