Charge Pump, 7-Channel Smart LED Driver with I2C Interface Features: Charge pump with automatic gain selection of 1×, 1.5×, and 2× for maximum efficiency 7 independent, programmable LED drivers 7 drivers capable of 30 mA (typical) 1 driver also capable of 60 mA (typical) Programmable maximum current limit (128 levels) Standby mode for <1 μA current consumption 16 programmable fade in and fade out time 0.1 sec to 5.5 sec Choose from linear, square, or cubic rates Fading override I2C-compatible interface for all programming Dedicated reset pin and built-in power-on reset (POR) Short-circuit, overvoltage, and overtemperature protection Internal soft start to limit inrush currents Input-to-output isolation during faults or shutdown Operation down to VIN = 2.5 V with undervoltage lockout (UVLO) at VIN = 2.0 V Available in a small 20-ball, 2.15 mm × 2.36 mm × 0.6 mm WLCSP or a 20-lead, 4 mm × 4 mm × 0.75 mm LFCSP

The AD9887A offers an analog interface receiver and a digital visual interface (DVI) receiver integrated on a single chip, supports high bandwidth digital content protection (HDCP), and is software and pin-to-pin compatible with the AD9887.ANALOG INTERFACEThe complete 8-bit, 170 MSPS, monolithic analog interface is optimized for capturing RGB graphics signals from personal computers and workstations. Its 170 MSPS encode rate capability and full-power analog bandwidth of 330 MHz support resolutions of up to 1600 × 1200 (UXGA) at 60 Hz. The interface includes a 170 MHz triple ADC with internal 1.25 V reference; a phase-locked loop (PLL); and programmable gain, offset, and clamp controls. The user provides only a 3.3 V power supply, analog input, and Hsync. Three-state CMOS outputs can be powered from 2.5 V to 3.3 V. The analog interface also offers full sync processing for composite sync and sync-on-green (SOG) applications. The AD9887A on-chip PLL generates a pixel clock from Hsync with output frequencies ranging from 12 MHz to 170 MHz. PLL clock jitter is typically 500 ps p-p at 170 MSPS. DIGITAL INTERFACEThe AD9887A contains a DVI 1.0-compatible receiver and supports resolutions up to 1600 × 1200 (UXGA) at 60 Hz. The receiver operates with true color (24-bit) panels in one or two pixel(s) per clock mode and features an intrapair skew tolerance of up to one full clock cycle. With the inclusion of HDCP, displays can receive encrypted video content. The AD9887A allows for authentication of a video receiver, decryption of encoded data at the receiver, and renewability of authentication during transmission, as specified by the HDCP v1.0 protocol. Fabricated in an advanced CMOS process, the AD9887A is provided in a 160-lead, surface-mount, plastic MQFP and is specified over the 0°C to 70°C temperature range. The AD9887A is also available in an RoHS compliant package.APPLICATIONS RGB graphics processing LCD monitors and projectors Plasma display panels Scan converters Microdisplays Digital TVs

Four White LED Backlight Driver Features: Drives 4 LEDs from a 2.6 V to 5.5 V (Li-Ion) input supply 1×/1.5×/2× fractional charge pump to maximize power efficiency 0.3% typical LED current matching Up to 88% power efficiency over Li-Ion range Powers main and sub display LEDs with individual shutdown Package footprint only 9 mm2 (3 mm × 3 mm) Package height only 0.75 mm Low power shutdown mode Shutdown function Soft start limiting in-rush current

Charge Pump Regulator for Color TFT Panels

The LT3797 is a triple output DC/DC controller designed to drive three strings of LEDs. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. The LT3797 includes an integrated DC/DC converter to produce a regulated 7.5V supply for the N-channel MOSFET gate drivers of the three channels. This high efficiency converter enables the part to operate from a wide input voltage range from 2.5V to 40V. The LT3797 is designed so that each converter can use the most suitable configuration to drive its LED load, whether step-up, step-down or a combination. Two key features enable this flexibility: first the LT3797 can sense output current at the high side of the LED string; and second, the voltage feedback pin, FBH, is referred to the ISP current sensing input. The CTRL inputs provide output current analog dimming capability. The TG drivers level shift the PWM signals to drive the gates of external LED-disconnect P-channel MOSFETs, allowing high PWM dimming range, and providing LED overcurrent protection and short-circuit protected boost capability.Applications Automotive and Industrial Lighting RGB Lighting Billboards and Large Displays

The LT3952A is a current mode step-up DC/DC converter with an internal, 60V, 80m? DMOS power switch. The LT3952A is specifically designed to drive high power LEDs in multiple configurations. It combines input and output current regulation loops with output voltage regulation to operate as a flexible current/voltage source.Programmable switching frequency with optional spread-spectrum modulation provides EMI reduction, while still allowing optimization of the external components for efficiency or component size. The LED current is programmable with an external sense resistor, and can be adjusted from zero to full scale with a voltage at the CTRL pin. The external PWM input provides LED ON/OFF control and 4000:1 dimming ratio, and an internal PWM generator delivers the efficiency of PWM dimming to standalone or I/O limited applications. The LT3952A is available in the thermally enhanced 28-lead TSSOP package.Applications Display Backlighting Automotive and Avionic Lighting Accurate Current-Limited Voltage Regulators

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.

Demonstration circuit 850A is a Boost LED Driver featuring the LTC3783 a boost/SEPIC/flyback LED driver controller. The demo board requires a 3V to 14.4V input and provides 360mA LED current at up to 25V. It incorporates an output overvoltage protection feature to limit output voltage to less than 27V if the LED string is inadvertently disconnected. The LT3783 features 1000:1 PWM dimming for brightness control and analog dimming control.

The LT3491 is a fixed frequency step-up DC/DC converter specifically designed to drive up to six white LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The device features a unique high side LED current sense that enables the part to function as a ?one wire current source;? one side of the LED string can be returned to ground anywhere, allowing a simpler one wire LED connection. Traditional LED drivers use a grounded resistor to sense LED current, requiring a 2-wire connection to the LED string.The 2.3MHz switching frequency allows the use of tiny inductors and capacitors. A single pin performs both shutdown and accurate LED dimming control. Few external components are needed: open-LED protection and the Schottky diode are all contained inside the tiny SC70 package. With such a high level of integration, the LT3491 provides a high efficiency LED driver solution in the smallest of spaces.Applications Cellular Phones PDAs, Handheld Computers Digital Cameras MP3 Players GPS Receivers

Demonstration circuit DC915 features the LT3466-1 high efficiency boost white LED driver and a step-up converter. There is one LED driver output for 6 or 8 WLEDs and a separate DC/DC converter that generates outputs for the LCD bias. VO1 drives 8 LEDs in series with 15mA LED current and VO2/VO3 can delivery ±15V at 10mA current. If the charge-pump circuitry which generates VO3 is removed (C4, C5 and D1), VO2 can deliver over 35mA of current. The input voltage range is 3V to 14V, but can go as low as 2.7V with slightly reduced output current.