Shenzhen DongKe Semicon DK125

DK125 is a secondary-feedback flyback AC-DC offline switching power supply controller IC. Designed with highly integrated CMOS circuitry, it features output short-circuit, secondary open-circuit, over-temperature, and over-voltage protection. The IC integrates a high-voltage power transistor and self-supply circuitry, requiring minimal external components and simplified transformer design (the transformer for isolated output circuits requires only two windings).

• Universal voltage input 90V–265V
• Built-in 700V high-voltage power transistor
• Integrated high-voltage constant-current startup circuit, no external startup resistor required
• Standby power consumption less than 0.3W
• 65KHz PWM switching frequency
• Patented self-supply technology, no external auxiliary winding required
• Built-in frequency dithering; automatically reduces operating frequency during standby to meet European Green Energy Standard (< 0.3W) while reducing output voltage ripple
• Built-in slope compensation circuit for stable operation at low voltage and high power output
• Frequency dithering reduces EMI filter cost
• Protection: over-temperature, over-current, over-voltage, output short-circuit, and secondary open-circuit
• 4KV ESD protection

• Power adapters
• LED power supplies
• Induction cooktops
• Home appliances such as air conditioners, DVD players, and set-top boxes