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.

The LT3478/LT3478-1 are 4.5A step-up DC/DC converters designed to drive LEDs with a constant current over a wide programmable range. Series connection of the LEDs provides identical LED currents for uniform brightness without the need for ballast resistors and expensive factory calibration.The LT3478-1 reduces external component count and cost by integrating the LED current sense resistor. The LT3478 uses an external sense resistor to extend the maximum programmable LED current beyond 1A and also to achieve greater accuracy when programming low LED currents. Operating frequency can be set with an external resistor from 200kHz up to 2.25MHz. Unique circuitry allows a PWM dimming range up to 3000:1 while maintaining constant LED color. The LT3478/LT3478-1 are ideal for high power LED driver applications such as automotive TFT LCD backlights, courtesy lighting and heads-up displays. One of two CTRL pins can be used to program maximum LED current. The other CTRL pin can be used to program a reduction in maximum LED current vs temperature to maximize LED usage and improve reliability.Additional features include inrush current protection, programmable open LED protection and programmable soft-start. Each part is available in a 16-pin thermally enhanced TSSOP Package.Applications High Power LED Driver Automotive Lighting

The ADD5211 is a four-string, white LED driver for backlight applications based on high efficiency, current mode, step-up converter technology. The boost controller drives an external MOSFET switch for step-up regulation from an input voltage of 4.5 V to 40 V and a pin adjustable operating frequency from 200 kHz to 1.2 MHz. An adjustable UVLO function is implemented to reduce input current during power-off.The ADD5211 provides four regulated current sinks for uniform brightness intensity. Each current sink can be driven from 40 mA to 200 mA; the LED driving current is pin adjustable using an external resistor. With an input PWM interface, the ADD5211 drives up to four parallel strings of multiple series connected LEDs.Additional features include LED short protection, LED open protection, boost output short protection, overvoltage protection, cycle-by-cycle current limit, and thermal shutdown for both the IC and the LED array. An open-drain fault output is also included. A programmable soft start is implemented to reduce inrush current during startup. Applications LCD monitor and TV LED backlights Industrial lighting

The ADN2871 laser diode driver (LDD) is designed for advanced SFP and SFF modules, using SFF-8472 digital diagnostics. The ADN2871 supports operation from 50 Mbps up to 4.25 Gbps.Average power and extinction ratios can be set with a voltage provided by a microcontroller DAC or by a trimmable resistor or digital potentiometer. The average power control loop is implemented using feedback from a monitor photodiode. The device provides bias and modulation current monitoring, as well as fail alarms and automatic laser shutdown (ALS). The device interfaces easily with the Analog Devices, Inc., ADuC7019 and ADuC7020 family of MicroConverter® devices and with the ADN2890, ADN2891, and ADN2892 family of limiting amplifiers to make a complete SFP/SFF transceiver solution. An SFP reference design isavailable.The product is pin-compatible with the ADN2870 dual-loop LDD, allowing the same design to work with either device. For dual-loop control applications, refer to the ADN2870 data sheet. The product is available in a space-saving 4 mm × 4 mm LFCSP specified over the −40°C to +85°C temperature range.Applications 1×/2×/4× Fibre Channel SFP/SFF modules Multirate OC3 to OC48-FEC SFP/SFF modules LX-4 modules DWDM/CWDM SFP modules 1GE SFP/SFF transceiver modules VCSEL, DFB, and FP transmitters

The LT3003 drives three separate strings of LEDs up to 350mA/channel with 3% accurate current matching, resulting in uniform LED brightness and intensity. This approach is superior to conventional methods of running three separate channels with external ballast resistors requiring expensive factory calibration.The LT3003 operates in boost, buck and buck-boost mode. A True Color PWM Dimming ratio of up to 3000:1 is achievable using a logic-level signal at the PWM pin for all modes without the need for external level-shifting circuitry. For applications with input supply above and below the output voltage of the LED strings, the LT3003 allows the LEDs to be returned to the input supply (buck-boost mode) instead of being limited to only SEPIC solutions.The LT3003 is ideal for high power LED driver applications such as TFT LCD backlighting and heads-up displays. Additional overtemperature outputs allow appropriate system management for increased reliability.The LT3003 is available in a small 10-pin MSE package.Applications High Power LED Ballaster Automotive Lighting Video Cameras TFT LCD Backlighting

LED Lighting Development Tools LT3791 4.7V-60V input to drive 25V of LEDs at 2A (scaleable to 100W)

LIGHTING DEVELOPMENT KITS;

Demonstration circuit DC2857A is a 36V 2A synchronous 2MHz boost LED driver featuring the LT3922-1. It drives a single string of LEDs at 330mA up to 34V when VIN is between 7V and 28V. It runs down to 4VIN with reduced ILED and can withstand VIN as high as 36V, but has overvoltage lockout (OVLO) set for 28V for this application. DC2857A runs at 2MHz switching frequency. Spread spectrum frequency modulation (SSFM) can be turned on with a simple jumper, reducing EMI. DC2857A comes with low EMI features including optimized layout, SSFM and input EMI filter. It passes CISPR 25 class 5 conducted and radiated EMI. It is protected against both open and short LED conditions and reports the faults. The LT3922-1 has an input voltage range from 2.8V to 36V. Its internal synchronous 2A 40V switches allow up to 34V of LEDs on the output with room for over voltage protection and overshoot during an open LED event. It has adjustable switching frequency between 200kHz and 2.5MHz. It can be synchronized to an external source or programmed with SSFM for low EMI. The PWMTG highside PWM MOSFET driver assists with short-circuit protection and versatility. LT3922-1 can be configured as a boost, boost-buck, or buck mode LED driver and maintain all of its low EMI, PWM dimming, and fault diagnostic features. The LT3922-1 can be PWM dimmed with an external PWM signal or an internally-generated PWM signal. DC2857A has a jumper that can be set to switch between internallygenerated PWM signal, externally-generated PWM signal, and no PWM signal (100% on). It can be analog dimmed with a control voltage on its control pin (CTRL). When run with both PWM dimming and spread spectrum, the spread spectrum aligns itself with the PWM signal for flicker-free operation. Small ceramic input and output capacitors are used to save space and cost. The board is designed with tiny, high frequency capacitors on both sides of the VOUT 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 37.5V if the LED string is opened, although it may reach almost 40V peak during transient from running LEDs to open. There is a protection diode from LED+ to GND to prevent negative ringing during a short-circuit. The output current can be monitored through the ISMON output pin. Undervoltage and overvoltage lockout can be adjusted on the circuit with a few simple resistor choices. There is an EMI filter on the input of DC2857A. Please follow the recommend layout and four-layer thickness of DC2857A for low EMI applications. The LT3922-1 data sheet gives a complete description of the part, operation and applications information. The LT3922EUFD-1 is assembled in a 28-lead plastic 4mm × 5mm QFN package with a thermally enhanced ground pad. Proper board layout is essential for maximum thermal performance. See the data sheet section Layout Considerations.

DC1039A-A: Demo Board for the LTC3207 600mA Universal Multi-Output LED/CAM Driver.