PMIC - LED Drivers

LT3519EMS#PBF LED drivers provide superior performance in various lighting applications. Featuring an integrated PWM dimming circuit and robust protection features, the drivers guarantee reliable operation of LED systems. It offers up to 400mA of constant current output with precision accuracy of 2% for all output current levels.

The LT3519EMS#PBF features a wide input voltage range of 3.0V to 30V, providing an exceptional design flexibility. Operating from a wide input voltage range, it enables a single LT3519EMS#PBF to power multiple LED strings in series, eliminating the need for multiple power supplies.

Features and Benefits of LT3519EMS#PBF LED Drivers

• Wide input voltage range (3.0V to 30V)
• Integrated PWM dimming circuit
• Up to 400mA of constant current output
• Small and thin TSSOP-16 and TQFN-16 packages
• Minimum external component count
• Excellent efficiency and thermal performance

Applications

• LED Backlighting for LCD and TV Monitors
• LED Lighting for Automotive, Industrial and General Lighting Applications
• General Purpose Constant Current Regulators

Working Principle

The LT3519EMS#PBF LED driver consists of an internal switching regulator, a dimming control circuit, and a power MOSFET. When the power switch is enabled, output current is provided by the regulator and accurately monitored by the external current sense resistor. By varying the voltages on the ENABLE and DIM pins, the dimming circuit will adjust the current level to various levels, allowing for smooth dimming of the LED load.

The internal switching regulator provides a regulated output voltage that is lower than the input voltage. The voltage across thefeedback resistor sets the output current to a level determined by an external resistor connected between the FB and GND pins. This current is supplied to the load through a MOSFET switch connected to the output.

The LT3519EMS#PBF includes two dimming control pins, ENABLE and DIM. ENABLE allows the user to turn the device on and off, while DIM serves as an input for a PWM signal. The duty cycle of the PWM signal is monitored by an internal circuit, which varies the peak current in the inductor to produce pulse width modulation (PWM) of the output current. This PWM output current can be used to vary the intensity of the LED load.