LM3447 Flyback Controller for LED Lighting Evaluation Module Board

TPS92515HV-Q1 Buck LED Driver Evaluation Board

LM36923H Highly Efficient Triple-String White LED Driver Evaluation Module

DC805A: Demo Board for the LTC3216 1A Low Noise High Current LED Charge Pump with Independent Torch/Flash Current Control.

Automotive Displays LCD and CRT Compatible RGB Amplifiers Coaxial Cable Drivers Low Voltage High Speed Signal Processing Set Top Boxes

DC871A-A: Demo Board for the LTC3215 700mA Low Noise High Current LED Charge Pump.

DC902A-B: Demo Board for the LTC3214 500mA Camera LED Charge Pump.

applications such as automotive TFT LCD backlights, courtesy lighting and heads-up displays. One of

Demonstration circuit 976 is a Quadruple High Power LED Driver in Buck Mode featuring the LT3476EUHF. The LT3476 is a quad output, multitopology DC/DC converter designed to operate as a current source for driving high current LEDs. Each of the four regulators on the demo circuit is independently operated. The VIN power supply for the IC ranges from 2.8V to 16V. The PVIN power supply for the buck regulators ranges up to 33V. On the demo circuit, the default current for each output channel is 350mA but it can be adjusted up to 1.05A via resistor dividers at the VADJ pins. The output current should not exceed the rated current of the LEDs used. If 1W LEDs, such as the Lumileds Luxeon LEDs, are used, 350mA current is the maximum. 1A output current is reserved for 3W LEDs, such as Luxeon III. The input voltage is limited by the CAP pin overvoltage protection threshold. As a result, each channel of the demo circuit can drive up to 27V total LED voltage.

Demonstration circuit 2788A is a boost LED driver featuring the LT®3950. This demonstration circuit powers a string of LEDs at 330mA. The step-up topology can be used to drive a string of up to 28V of LEDs as assembled. The maximum output voltage capability of the LT3950 is 60V. DC2788A runs from an input voltage range of 6V to 24V as built. It also runs at 2MHz and has the capability to turn on spread spectrum frequency modulation (SSFM) for a frequency range of 2.0MHz to 2.5MHz. Dimming control can be achieved with analog dimming or PWM dimming—either from an external or internally-generated clock source. DC2788A features undervoltage lockout (UVLO) set at 6.6V with a 1.0V hysteresis for turn-on. The UVLO voltage, LED current, output voltage range, switching frequency, brightness control, SSFM, and the topology can all be adjusted with simple modifications to the demonstration circuit. LT3950 is a monolithic 1.5A peak switch current, 60V LED driver. The guaranteed peak switch current rating of the IC is 1.5A and this is important to know when calculating maximum output current at a given LED voltage and input voltage for a boost converter. The LT3950 features SSFM and a well-controlled SW node for low emissions. A frequency range of 200kHz to 2MHz and a high-side PWMTG PWM-dimming MOSFET makes this a very versatile IC for many applications. It can be used for boost, buck-boost mode and buck mode LED driver applications. The PWMTG MOSFET not only provides high PWM dimming ratio capability, but it also serves as a short-circuit protection device. The FAULT flag indicates when there is either a short-circuit or open-LED fault at the output. The demo circuit is designed to be easily reconfigured to suit other applications, including the example schematics in the data sheet. Consult technical support for assistance. High voltage operation, 3V input voltage operation, multiple topologies, small-and-compact size, fault protection, low EMI, and multiple brightness control options make the LT3950 flexible and powerful for compact, noise-sensitive LED driver solutions. The LT3950JMSE featured on this demo circuit is available in a thermally enhanced 16-lead plastic MSOP package. The LT3950 data sheet must be read in conjunction with this demo manual to properly use or modify demo circuit DC2788A.