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.

The LTC3201 is an ultralow noise, constant frequency, charge pump DC/DC converter specifically designed for powering white LEDs. The part produces a low noise boosted supply capable of supplying 100mA of output current. LED current is regulated for accurate and stable backlighting. A 3-bit DAC provides output current adjust for brightness control.Low external parts count (one small flying capacitor and three small bypass capacitors) and small MSOP-10 package size make the LTC3201 ideally suited for space constrained applications. An input noise filter further reduces input noise, thus enabling direct connection to the battery. High switching frequency enables the use of small external capacitors.The LTC3201 contains overtemperature protection and can survive an indefinite output short to GND. Internal soft-start circuitry also prevents excessive inrush current on start-up. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1?A.Applications White LED Backlighting Programmable Boost Current Source

DC507A: Demo Board for the LT1937 White LED Step-Up Converter in SC70 and ThinSOT.

The LTC3202 is a low noise, constant frequency charge pump DC/DC converter that uses fractional conversion to increase efficiency in white LED applications. The part can be used to produce a regulated voltage or current of up to 125mA from a 2.7V to 4.5V input. Low external parts count (two flying capacitors and two small bypass capacitors at VIN and VOUT) make the LTC3202 ideally suited for small, battery-powered applications.An internal 2-bit DAC allows LED current to be adjusted for LED brightness control. The LTC3202 also has thermal shutdown protection and can survive a continuous short-circuit from VOUT to GND. Built-in soft-start circuitry prevents excessive inrush current during start-up. High switching frequency enables the use of small external capacitors. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1?A.The LTC3202 is available in the 10-pin MSOP and 3mm x 3mm DFN packages.Applications White LED Backlighting Programmable Boost Current Source?

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

The LT3479 is a current mode, fixed frequency step-up DC/DC converter with an internal 3A, 42V switch. Efficiencies of up to 89% can be achieved in typical applications. It features a programmable soft-start function to limit inductor current during start-up and inrush current protection to protect the LT3479 during shorts and line transients. Both inputs of the error amplifier are available to the user allowing positive and negative output voltages. Through an external resistor, the user can program the switching frequency from 200kHz to 3.5MHz. The low profile (0.75mm) 14-pin, 4mm ? 3mm DFN package provides excellent thermal performance in a small footprint. The LT3479 is also available in a thermally enhanced 16-pin TSSOP package.Applications High Power LED Driver DSL Modems Distributed Power

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

The LT8391 is a synchronous 4-switch buck-boost LED controller that regulates LED current from input voltage above, below, or equal to the output voltage. The proprietary peak-buck peak-boost current mode control scheme allows adjustable and synchronizable 150kHz to 650kHz fixed frequency operation, or internal ?15% triangle spread spectrum operation for low EMI. With 4V to 60V input, 0V to 60V output, and seamless low noise transitions between operation regions, the LT8391 is ideal for LED driver and battery charger applications in automotive, industrial, and battery-powered systems.The LT8391 provides both internal (up to 128:1) and external (up to 2000:1) LED current PWM dimming with a high-side PMOS switch. Two CTRL pins provide flexible 20:1 analog dimming with ?3% LED current accuracy at 100mV full scale. Fault protection is provided to detect an open or short LED condition, during which the LT8391 retries, latches off, or keeps running. Switching Frequency Max Output Power LT8391 Adjustable 150kHz - 650kHz 450W+ LT8391A 2MHz 50W+ APPLICATIONS Automotive Head Lamps/Running Lamps High Power LED Lighting

3A, Full Featured DC/DC Converter with Soft-Start and Inrush Current Protection Features: Wide Input Voltage Range: 2.5V to 24V 3A, 42V Internal Switch High Efficiency Power Conversion: Up to 89% Soft-Start Frequency Set by External Resistor: 200kHz to 3.5MHz Protection Against Input Short Circuits and Hot Plugging Low VCESAT Switch: 0.3V at 2.5A (Typical) Capable of Positive and Negative Outputs Available in Thermally Enhanced 14-Lead (4mm × 3mm) DFN and 16-Lead TSSOP Packages

PWM LED Driver and Boost, Flyback and SEPIC Controller Features: True Color PWM™ Delivers Constant Color with 3000:1 Dimming Ratio Fully Integrated Load FET Driver for PWM Dimming Control of High Power LEDs 100:1 Dimming from Analog Inputs Wide FB Voltage Range: 0V to 1.23V Constant Current or Constant Voltage Regulation Low Shutdown Current: IQ = 20μA 1% 1.23V Internal Voltage Reference 2% RUN Pin Threshold with 100mV Hysteresis Programmable Operating Frequency (20kHz to 1MHz) with One External Resistor Synchronizable to an External Clock Up to 1.3fOSC Internal 7V Low Dropout Voltage Regulator Programmable Output Overvoltage Protection Programmable Soft-Start Can be Used in a No RSENSE™ Mode for VDS < 36V 16-Lead DFN and TSSOP Packages