AS2561

High PF Isolated PWM Dimming (FLYBACK) External MOS Constant Current Chip

The AS2561 is a high-performance, quasi-resonant (QR) Boost type (Boost) constant voltage power factor correction (PFC) controller. The chip adaptively operates in critical on-mode (CRM) and discontinuous on-mode (DCM). Full load when the chip works in CRM; When the load is reduced, the chip works in DCM, and the working frequency is reduced to improve the system efficiency. By optimizing the CRM/DCM control algorithm and input line voltage feedforward compensation, the chip can easily achieve high power factor (PF) and low input harmonics (THD) performance, even if the chip operates in DCM. The AS2561 has a built-in high-voltage start and power supply circuit, which can be quickly started and powered without external power supply.

In addition, degaussing detection technology without auxiliary windings simplifies system design and reduces production costs. The AS2561 is fully integrated with protection features, including: VDD Undervoltage protection (UVLO), VDD Overvoltage protection (VDD OVP), input Undervoltage protection (BOP), output Undervoltage protection (UVP), output Overvoltage protection (OVP), cycle current Limit (OCP), abnormal overcurrent protection (AOCP), overheat protection (OTP), and pin open short circuit protection.

Product features:

• Power factor >0.95, THD<8%

• Standby power consumption <75mW

• Built-in 700V high voltage power supply circuit, start time <200ms

• Light load efficiency optimization and standby loss optimization

• Light load THD optimization

• Dynamic performance optimization

• Supports single-winding inductance

• Built-in ±2% (@Tj = 25ºC) constant voltage reference voltage

• internal complete protection function

• Encapsulation type SOP-8

Product Application:

• LED dimming power supply