Description

The PMP10596 reference design is an LED driver based on SIMPLE SWITCHER® LM46002 buck regulator. The driver board takes 24V +/-25% input voltage and supplies700mA 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.