Adaptive LED Current Ripple Suppressor with PF Above 0.9

Diodes Incorporated announced the availability of the AL5822 LED current ripple suppressor. The device, which is intended for commercial and industrial lighting applications, provides high levels of ripple suppression while maintaining a high power factor.

The company notes that it is now mandatory to meet regulatory requirements for suppressing low-frequency ripple (100Hz to 120Hz) in LED lighting applications for numerous markets, enforced through standards that include the California Energy Commission Title 24.

The AL5822 provides a high level of ripple current suppression in single-stage, high-power LED installations, even when Triac or PWM dimming is being utilized to vary the light level. This ensures that LED lights exhibit no evidence of flicker or strobing across the entire dimming range, while maintaining a high power factor.

Diodes designed and tested the AL5822 adhere to the Title 24 building code requirement of having less than 30% flicker. The results reveal that the AL5822 suppresses over 97% of ripple while still achieving a power factor of above 0.9.

It monitors the current flowing through the LEDs and adjusts the drive voltage for the external MOSFET to compensate for ripple. This control loop holds the MOSFET in the saturation region to deliver a constant current.

With support for various pre-stage circuits, the AL5822 can work with a number of drivers, including the AL1665 single stage PFC flyback buck/boost controller, also from Diodes Incorporated. Integrated features of the AL5822 remove the need for discrete, magnetic components, minimizing the overall bill of materials.

Coupled with a pre-stage APFC LED driver, Diodes Incorporated says that the AL5822 can efficiently suppress the low frequency (100Hz/120Hz) LED current ripple from the APFC output, thereby eliminating the low frequency flickering of various LED lamps.

The AL5822 adopts high-efficiency driving mechanism. It can automatically adapt to different LED chains' voltage and current, to eliminate the LED current ripple, meanwhile minimize the power consumption on the Power MOSFET.

The AL5822 has built-in protections, such as Over-Temperature- Protection (OTP), Over-Current-Protection (OCP) and LED Short-Circuit Protection (SCP).

AL5822 operates over an input voltage of 24VAC to 305VAC. Safety features include LED short-circuit, over-current, and over-temperature protections.

The AL5822 is available in the SOT26 package.

Features

• High Efficiency
• Support Various Kinds of APFC Pre-Stage Circuit
• Simplified External Bill of Materials (BOM)
• No Need for Magnetic Components
• Wide Output Voltage and Current Range
• Tuneable LED Current Ripple Ratio
• Flickering Free
• LED Short-Circuit Protection (SCP)
• Over-Current Protection (OCP)
• Over-Temperature Protection (OTP)
• SOT26 Package
• Totally Lead-Free & Fully RoHS Compliant
• Halogen and Antimony Free. "Green" Device