DC1947A: Demo Board for the LT3799-1 Offline Isolated Flyback LED Controller with Active PFC.

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

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

Demonstration circuit 2020A is a 60VIN, 80VOUT LED driver. It generates its own PWMOUT waveform from its internal PWM generator for accurate PWM dimming with up to 33:1 brightness ratio. It accepts an input voltage from 5V to 60V and drives up to 67V of LEDs at 300mA (when PVIN is less than VLED). DC2020A features both PWM and analog dimming of the LED string. It has an OPENLED flag that indicates when the LED string has been removed. DC2020A features high efficiency at 350kHz switching frequency. At high LED string voltages up to 67V and 300mA of LED current, the single switch controller has 92% efficiency. The LT3955 has an internal 80V, 3.5A switch that simplifies the schematic and layout.

DC1205A: Demo Board for LT3592 500mA Wide Input Voltage Range Step-Down LED Driver with 10:1 Dimming.

Demonstration circuit 2404A is a 36V synchronous buckboost LED driver featuring the LT3942. It drives a single string of LEDs up to 14V at 1A when VIN is between 9V and 36V and will run down to 3VIN with reduced ILED. DC2404A runs at 2MHz switching frequency with spread spectrum frequency modulation (SSFM) disabled. When enabled, SSFM spreads the switching frequency of the LT3942 from fSW to fSW + 25% for reduced EMI performance. The LT3942 has an operating input voltage range of 3V to 36V. It has internal, synchronous 40V switches for high efficiency and small size. It has an adjustable switching frequency between 300kHz and 2MHz. The LT3942 can by synchronized to an external source, programmed with SSFM enabled for low EMI, or set to normal operation. The LT3942’s integrated PWMTG high-side PWM MOSFET driver assists with short-circuit protection of the output, as well as PWM dimming of the connected LEDs. The LED string can be PWM dimmed with an external PWM signal or can be dimmed using the internally generated PWM signal. DC2404A has jumpers that can be set to switch between internally and externally generated PWM signals. The external PWM setting defaults to 100% on with no PWM signal applied. The LT3942 can also be analog dimmed by placing a controllable DC voltage on the CTRL pin. When running PWM dimming with SSFM enabled, the SSFM aligns itself with the PWM signal for flicker free operation. This applies to both internal and external PWM dimming. Small ceramic input and output capacitors are used to save space and cost. The board is designed with tiny, high frequency capacitors placed near the PVIN and PVOUT pins for a reduction in radiated EMI. The open LED overvoltage protection uses the IC’s constant voltage regulation loop to regulate the output to approximately 17V peak if the LED string is opened. The output current can be monitored through the ISMON output pin. Undervoltage lockout can be adjusted on DC2404A with a few simple resistor choices. There is a small ferrite bead EMI filter on the input and output of DC2404A. These filters, combined with proper board layout and SSFM, are effective in reducing EMI. Please follow the recommended layout and four-layer PCB thickness of DC2404A for low EMI applications. The LT3942 can operate as a constant current LED driver as well as a constant voltage regulator. Small changes to the circuit allow for constant output voltage regulation. The LT3942 data sheet gives a complete description of the part, operation, and applications information. The data sheet must be read in conjunction with this demo manual for demonstration circuit 2404A. The LT3942EUFD is assembled in a 28-lead plastic QFN (UFD) package with a thermally enhanced exposed ground pad. Proper board layout is essential for maximum thermal performance. See the data sheet section Layout Considerations.

LM3410X Boost LED Driver Evaluation Board; 190mA; Overvoltage Protection; 4 Series LEDs

Evaluation Module for General Purpose PWM Controller with 10V Turn-on Threshold for LED Lighting

LM3401 MR16 Bulb Reference Design for Non-Dimming & Dimming LED Applications

Evaluation Module for LP8557 High Efficiency White LED Backlight Driver with I2C Control