Boost driver for long LED strings (LED串驱动器)
The long strings of LEDs commonly found in TV and display backlighting, street lights, and parking garage lights require a current driver capable of producing high voltages. This reference design provides such a driver using the MAX16834, and demonstrates how very-high dimming ratios can be obtained.
VIN: 24VDC ±5% (at 1.22A)
VLED Config.: 23 LEDs in series (75V) at 350mA.
Dimming: As low as a 3.33µs on-pulse (3000:1 dimming ratio when the dimming frequency = 100Hz).
Note: this design has been built and tested. However, detailed testing has not occurred and there may be nuances that are yet to be discovered.
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Figure 1. The LED driver board.
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Figure 2. Schematic of the LED driver. 
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Figure 3. Layout of the LED driver.
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Figure 4. Bill of materials.
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Figure 5. Design spreadsheet. To get the spreadsheet for use in your design, contact your local Maxim sales office.
Figure 6. Drain voltage and current-sense resistor voltage (50mΩ).
Figure 7. Drain voltage risetime.
Figure 8. Output voltage (AC coupled) and sense-resistor voltage.