ON Semiconductor FAN7687A - Critical Conduction Mode PFC Controller

The ON Semiconductor FAN7687A is a sophisticated power factor correction (PFC) controller specifically designed for use in applications requiring high efficiency and power density. This device operates in critical conduction mode (CRM), which is also known as boundary mode or transition mode, making it highly suitable for systems that need to meet stringent power factor requirements such as ENERGY STAR® or the European Union's IEC61000-3-2 standards.

With its integrated high-voltage startup circuit, the FAN7687A ensures a fast and low-loss startup sequence, reducing the overall power consumption during the initial phase. The device is equipped with a zero-current detector (ZCD) to ensure that each power switch only turns on at the point of zero current, minimizing switching losses and enhancing the overall efficiency of the power supply.

The FAN7687A features various protection mechanisms to safeguard the system under abnormal conditions. Over-voltage protection (OVP) and open-loop protection prevent damage to the controller and the power supply during no-load or high-voltage scenarios. Additionally, the built-in over-temperature protection (OTP) adds an extra layer of safety, ensuring the device operates within safe temperature limits.

One of the key benefits of the FAN7687A is its ability to operate at variable switching frequencies, which allows for the optimization of the magnetic components in the design, leading to a reduction in size and cost. Furthermore, the device's soft-recovery feature minimizes EMI emissions, a critical consideration in modern electronic equipment.

ON Semiconductor's FAN7687A is an ideal solution for a wide range of power applications, including but not limited to power supplies for LCD TVs, desktop computers, servers, and telecom equipment. Its robust design, combined with energy-saving features and protections, make it a reliable and efficient choice for engineers looking to enhance their power systems' performance.