FM2842

FM2842 is a highly integrated quasi-resonant flyback controller IC designed for high-performance offline flyback switching power supplies. It integrates an internal high-voltage startup circuit and enables no-load power consumption below 30mW. FM2842 features comprehensive protection functions, including OPP, OVP, OSCP, AC line loss protection, and primary-side abnormal overcurrent fault protection, preventing circuit damage under various abnormal conditions and enhancing overall safety. In addition, FM2842 incorporates frequency jittering to effectively reduce EMI. Under light load, the minimum operating frequency is limited and the IC enters burst mode operation to eliminate audio noise. The chip is housed in a SOP-9 package to save PCB space, making it the ideal solution for low-power, low-cost, high-efficiency designs.

Applications

• AC-DC Adapters and Chargers
• Flyback Switching Power Supplies

Key features

• Abnormal overcurrent fault protection for winding short circuit or saturation detection
• Valley switching, valley lockout, and noiseless operating mode
• Built-in high-voltage startup circuit and brown-out detection
• Integrated X2 capacitor discharge function in high-voltage startup pin
• Built-in 4ms soft-start time
• Adjustable maximum switching frequency up to 500KHz
• OTP fault detection pin
• VCC operating range from 9V to 28V
• Overvoltage protection triggered when VCC exceeds 28V
• Frequency foldback mode with minimum frequency clamp at 25kHz for improved light-load efficiency
• Audio-noise-free light-load cycle-skipping mode
• MPCM mode for rapid switching frequency reduction under light load
• Adjustable over power protection (OPP)
• Integrated internal over-temperature protection
• No-load power consumption below 30mW
• Frequency dithering for EMI reduction
• SOP-9 package