43 W flyback converter reference design board helps accelerate design of LED drivers
Infineon has released a reference design board which provides a ready-to-use blueprint for a 43 W flyback converter producing a constant-voltage output in two-stage LED drivers. The board is based on the Infineon ICL8820 single-stage flyback converter controller.
The REF_ICL8820_LED_43W_JT is a constant-voltage, secondary-side regulated system. It is intended for use with a constant-current converter in a two-stage LED driver circuit. Two-stage topologies are growing in popularity because of the scalability of the power output on the primary side, as well as the value of the features on the secondary side. The ICL8820 is suitable for luminaires rated for up to a 125 W power output.
Complementing the REF_ICL8820_LED_43W_JT, Infineon also supplies the REF_ILD8150_DC_1.5A board, based on the ILD8150, an 80 V buck LED driver IC offering hybrid dimming down to 0.5%. The ILD8150 is rated for average output current up to 1.5 A. Together, the two boards implement a complete constant voltage/constant current LED driver system. Another choice available from Infineon for constant current conversion is the DEMO_BCR601_60V_IVCTRL board, demonstrating the BCR601, a 60 V linear LED controller IC with voltage feedback to the primary side.
The REF_ICL8820_LED_43W_JT 43 W reference design is provided with two regulation circuits. Both circuits are designed as plug-and-play solutions; at least one has to be connected to the main board. Of the two boards, the TL431-based option has a lower cost and lower standby power consumption. The board based on an operational amplifier provides 30 mW better performance.
In this reference design, the ICL8820 produces a high power factor and low total harmonic distortion in both full- and low-load conditions. The ICL8820 also offers high conversion efficiency and low EMI without compromising quality of light. In particular, the device’s built-in jitter function eases EMI certification, while eliminating the need for additional circuitry required by competing controllers.
In its default set-up, the reference design board is assembled with a start-up circuit based on a BSS126I depletion-mode MOSFET on a small adapter board. This set-up offers the lowest standby losses. If low standby consumption is not required, the start-up circuit can be changed to a resistive scheme.
The fully-featured variant of the ICL88xx family, the ICL8820 is ideal for use in on-off LED drivers, and to support dimming down to 0.1%, including dim-to-off. The device achieves very low standby power of less than 100 mW.
The ICL8800 is the lowest-cost member of the family. The ICL8810 offers low standby power, while the ICL8820 combines low standby power and the jitter function.
The ICL8800 and ICL8810 flyback converter controllers are also backed by reference design boards.