The REF_ICL8820_LED_43W_JT is a 43W reference design featuring Infineon’s flyback controllerICL8820. The board is a constant voltage (CV) secondary-side regulated (SSR) system and is intended to be used with a constant current (CC) converter forLED lighting applications. Two-stage topologies are growing because of the convenient scalability of power on the primary side as well as of the features on the secondary side. REF_ICL8820_LED_43W_JT is designed asplug- and-play solution. As a default setup, the reference design board is assembled with a start-up circuit based on a depletion-mode MOSFETBSS126Ion a very small adapter board. This setup offers the lowest standby losses. If low standby consumption is not necessary as an option, the start-up circut can be changed to a resistive start-up. This reference design is provided with two regulation circuits. Both circuits are designed as plug and play solutions, but at least one has to be connected to the main board. The two boards shall show the trade-off between cost; here the TL431 board offers a low-cost solution, and standby performance, while the op-amp board shows an overall 30mW better performance.