Diodes Incorporated AP3128: Peak-Current Controlled Multi-Mode PWM Controller for Cost-Effective Offline Flyback Converters

Diodes' AP3128 is a peak-current control, multi-mode PWM controller optimized for offline flyback converters. It features low standby power, frequency foldback for efficiency, and comprehensive protection features.

The AP3128 from Diodes Incorporated stands out as a peak-current control, multi-mode PWM controller designed specifically for optimizing the performance of cost-effective offline flyback converters. This innovative IC combines quasi-resonant and continuous current mode (QR+CCM) operation to deliver high efficiency and low standby power consumption.

During no load or light load conditions, the AP3128 automatically switches to burst mode, minimizing standby power consumption and enhancing energy efficiency. To ensure a noise-free operation, the minimum switching frequency is carefully set. As the load on the converter increases, the IC seamlessly transitions into QR mode with frequency foldback, enabling improved system efficiency and enhanced electromagnetic interference (EMI) performance.

One key feature of the AP3128 is its ability to limit the maximum switching frequency to around 105 kHz, effectively controlling QR frequency and reducing switching power losses. Additionally, the built-in frequency dithering function plays a crucial role in reducing EMI emissions, ensuring compliance with stringent regulatory standards.

Moreover, the AP3128 incorporates internal piecewise linear line compensation to guarantee a constant output power limit across the entire universal line voltage range. The IC also offers a host of comprehensive protection features, including brown-out protection (BNO), cycle-by-cycle current limit (overcurrent protection - OCP), VCC overvoltage protection (VOVP), secondary-side output overvoltage protection (SOVP), undervoltage protection (SUVP), internal overtemperature protection (OTP), overload protection (OLP), and pins' fault protection.

Packaged in an SO-8 form factor, the AP3128 is not only versatile but also robust, making it an ideal choice for a wide range of offline flyback converter applications. With its advanced features, efficient operation, and comprehensive protection mechanisms, the AP3128 sets a new standard for cost-effective and reliable power management solutions in various industries.