The PMP10596 reference design is an LED driver based on SIMPLE SWITCHER® LM46002 buck regulator. The driver board takes 24V +/-25% input voltage and supplies 700mA output current to drive up to 4 LEDs in series. The LM46002 is a 60V, 2A synchronous buck regulator with integrated FETs, and in this design it is configured as a high efficiency constant current converter. This is accomplished by using the voltage across a current sense resistor as the feedback signal. To reduce the sense resistor power loss, a 2V voltage reference is used to bias the FB pin via a resistor network, and, as a result, the equivalent feedback reference voltage becomes 0.35V, lower than the 1V feedback of the LM46002. The reference board employs 3 dimming schemes, which allows the output current to be adjusted via the potentiometer, an analog voltage or a PWM signal. It also offers easy and flexible control to dim the LED brightness and adds output overvoltage protection from LED open-circuit failure.
Features
• 24V +/-25% input voltage range, drive up to 4 LEDs
• 94% efficiency driving 4 LEDs
• Simple voltage bias circuit to reduce sense resistor lost
• 3 flexible dimming options
• LED open circuit protection
• This circuit board is tested, and the design files and test report are included.
Parts Include:
LM4040-N Precision Micropower Shunt Voltage Reference
LM46002 SIMPLE SWITCHER® 3.5V to 60V, 2A Synchronous Step-Down Voltage Converter
Learn more by downloading the reference design below
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