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LM3404 LED driver circuit

Using the LM3404 are monolithic switching regulator can be designed a very simple constant current driver for high power LEDs. This LED driver electronic project is ideal for automotive, industrial, and general lighting applications .
LM3404 contain a high-side N-channel MOSFET switch with a current limit of 1.5A (typical) for step-down (Buck) regulators.

Hysteretic controlled on-time and an external resistor allow the converter output voltage to adjust as needed to deliver a constant current to series and series-parallel connected LED arrays of varying number and type.

The LED driver circuit require a regulated DC voltage input of 48V ±10% . Using this constant current LED driver will power ten series-connected LEDs at 500 mA ±10% with a ripple current of 50 mAP-P or less. The typical forward voltage of the LED module in thermal steady state is 35V, hence the average output voltage will be 35.2V.
As you can see this constant current LED driver circuit design , require few external electronic components and due to a compact design it can be used in some light applications where space is critical .
The input voltage of 48V requires Schottky diodes with a reverse voltage rating greater than 50V.

The bootstrap capacitor CB should always be a 10 nF ceramic capacitor with X7R dielectric. A 25V rating is appropriate for all application circuits. Electrical efficiency, η, should not be confused with the optical efficacy of the circuit, which depends upon the LEDs themselves. Total output power, PO, is calculated as: PO = IF x VO = 0.5 x 35.2 = 17.6W .
In the table bellow you can see all components that are required for this LED driver project .
White Led driver circuit diagram design using LM3404 integrated circuit

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