onsemi PMIC - PMIC - PFC (Power Factor Correction) - NCP1937A1DR2G NCP1937A1DR2G

The NCP1937A1DR2G is a combination Power Factor Correction (PFC) and quasi-resonant flyback controller designed for compact and efficient switched-mode power supply applications, particularly in adapters. It operates in Critical Conduction Mode (CrM) to achieve near-unity power factor and features a maximum frequency clamp to enhance performance. This IC integrates essential functionalities for a robust PFC stage while minimizing the need for external components. It includes a proprietary valley-lockout circuitry for stable valley switching, operating down to the fourth valley, and employs a frequency foldback mode to reduce audible noise. The device supports skip mode operation, which optimizes efficiency during light load conditions and maintains low standby power consumption. Key specifications include a wide VCC range from 9 V to 30 V, built-in overvoltage protection, and a high-voltage startup circuit. The NCP1937A1DR2G also features integrated fault detection, temperature shutdown, and adjustable PFC disable thresholds based on output power. The device is packaged in a 20-pin SOIC format, making it suitable for various applications requiring efficient power management.