STEVAL-ILL007V1: 1 to 3 LEDs @ 0.35, 0.7, or 1A

The evaluation board is designed to display the full functionality of L5973D as a LED driver to drive one to three 1W, 3W as well as 5W LEDs at 12Vac input. The components selected for the demo board are optimized for 5W LED driver application.

Based on this circuit, there are nine different configurations with different input voltages and output power levels that could be derived by making minor components changes to the evaluation board. Table 1. (User Guide) shows the component changes needed in order to obtain each configuration. The final schematics and bill of materials for each configuration are shown in the subsequent pages.

On the evaluation board, the value of Rs is selected by jumpers J2 and J4. When both J2 and J4 are open, the output current is set to 350mA. Inserting each jumper connects a 0.68Ω resistor in parallel with the 0.68Ω Rs. With J2 shorted, the output current will be set to 700mA and the output current becomes 1A with both J2 and J4 shorted.

Depending on the input voltage, this constant current LED driver has been configured to drive 1 ~ 8 LEDs @ 350mA, 1 ~ 4 @ 700mA, or 1 ~ 3 at 1.05 A. (As a Buck, the input voltage must be greater than the output voltage)

* Based on obsolete board 497-5074-ND.