DK912

DK912 is a primary-side flyback AC-DC switching power supply controller IC. It integrates a 700V high-voltage switching power transistor and a primary-side peak current sensing circuit. The IC also incorporates primary-side feedback constant-current/constant-voltage control, a self-supply circuit, and output cable compensation. Designed with highly integrated CMOS circuitry, it requires minimal external components and simplifies transformer design — the isolation output transformer requires only two windings.

Applications

• LED power supplies
• Power adapters
• Induction cookers, air conditioners, DVD players, set-top boxes, and other small home appliances

Key features

• Universal voltage input 85V–265V
• Built-in 700V high-voltage power transistor
• Integrated high-voltage constant-current startup circuit — no external startup resistor required; patented primary-side feedback control algorithm eliminates auxiliary winding
• Patented self-supply technology — no external auxiliary winding required
• Built-in PWM oscillator with frequency dithering for excellent EMC performance
• ±2% constant-voltage accuracy, ±5% constant-current accuracy
• Over-temperature, over-current, over-voltage, and output short-circuit protection
• 4KV ESD protection