Analog Devices

The LT3745-1 integrates a 16-channel LED driver with a 55V buck controller. The LED driver lights up to 75mA/36V of LEDs in series per channel, and the buck controller generates an adaptive bus voltage supplying the parallel LED strings. Each channel has individual 6-bit dot correction current adjustment and 12-bit grayscale PWM dimming. Both dot correction and grayscale are accessible via a serial data interface in LVDS logic. A ±4% LED current matching and a 0.5μs minimum LED on-time can be achieved at 50mA per channel.The LT3745-1 performs full diagnostic and protection against open/short LED and overtemperature fault. The fault status is sent back through the serial data interface. The 30MHz fully buffered, cascadable LVDS serial data interface makes the chip extremely suitable for large screen LCD dynamic backlighting and mono-, multi-, full-color LED displays. The LT3745 uses a TTL/CMOS serial data interface instead of LVDS.ApplicationsLarge Screen Display LED BacklightingMono-, Multi-, Full-Color LED DisplaysLED Billboards and Signboards

The LT3746 integrates a 32-channel LED driver with a 55V buck controller. The LED driver lights up to 30mA/13V of LEDs in series per channel, and the buck controller generates an adaptive bus voltage supplying the parallel LED strings. Each channel has individual 6-bit dot correction current adjustment and 12-bit grayscale PWM dimming. Both dot correction and grayscale are accessible via a serial data interface in TTL/CMOS logic.The LT3746 performs full diagnostic and protection against open/short LED and overtemperature fault. The fault status is sent back through the serial data interface. The 30MHz fully-buffered, skew-balanced, cascadable serial data interface makes the chip extremely suitable for large screen LCD dynamic backlighting and mono-, multi-, full-color LED displays.ApplicationsLarge Screen Display LED BacklightingMono-, Multi-, Full-Color LED DisplaysLED Billboards and Signboards

The LT3748 is a switching regulator controller specifically designed for the isolated flyback topology and capable of high power. It drives a low side external N-channel power MOSFET from an internally regulated 7V supply. No third winding or opto-isolator is required for regulation as the part senses the isolated output voltage directly from the primary-side flyback waveform.The LT3748 utilizes boundary mode to provide a small magnetic solution without compromising load regulation. Operating frequency is set by load current and transformer magnetizing inductance. The gate drive of the LT3748 combined with a suitable external MOSFET allow it to deliver load power up to several tens of watts from input voltages as high as 100V.The LT3748 is available in a high voltage 16-lead MSOP package with four leads removed.ApplicationsIsolated Telecom ConvertersHigh Power Automotive SuppliesIsolated Industrial Power SuppliesMilitary and High Temperature Applications

The LT3750 is a flyback converter designed to rapidly charge large capacitors to a user-adjustable target voltage. A patented boundary mode control scheme* minimizes transition losses and reduces transformer size. The transformer turns ratio and two external resistors easily adjust the output voltage.* A low 78mV current sense accurately limits peak switch current and also helps to maximize efficiency. With a wide input voltage range, the LT3750 can operate from a variety of power sources. A typical application can charge a 100μF capacitor to 300V in less than 300ms.The CHARGE pin gives full control of the LT3750 to the user. TheDONEpin indicates when the capacitor has reached its programmed value and the part has stopped charging.ApplicationsEmergency Warning BeaconsProfessional Photoflash SystemsSecurity/Inventory Control SystemsHigh Voltage Power SupplyElectric FencesDetonators

The LT3751 is a high input voltage capable flyback controller designed to rapidly charge a large capacitor to a user-adjustable high target voltage set by the transformer turns ratio and three external resistors. Optionally, a feedback pin can be used to provide a low noise high voltage regulated output.The LT3751 has an integrated rail-to-rail MOSFET gate driver that allows for efficient operation down to 4.75V. A low 106mV differential current sense threshold voltage accurately limits the peak switch current. Added protection is provided via user-selectable overvoltage and undervoltage lockouts for both VCCand VTRANS. A typical application can charge a 1000μF capacitor to 500V in less than one second.The CHARGE pin is used to initiate a new charge cycle and provides ON/OFF control. TheDONEpin indicates when the capacitor has reached its programmed value and the part has stopped charging. TheFAULTpin indicates when the LT3751 has shut down due to either VCCor VTRANSvoltage exceeding the user-programmed supply tolerances.ApplicationsHigh Voltage Regulated SupplyHigh Voltage Capacitor ChargerProfessional Photoflash SystemsEmergency StrobeSecurity/Inventory Control SystemsDetonators

The LT3752/LT3752-1 are current mode PWM controllers optimized for an active clamp forward converter topology. A DC/DC housekeeping controller is included for improved efficiency and performance. The LT3752 allows operation up to 100V input and the LT3752-1 is optimized for applications with input voltages greater than 100V.A programmable volt-second clamp allows primary switch duty cycles above 50% for high switch, transformer and rectifier utilization. Active clamp control reduces switch voltage stress and increases efficiency. A synchronous output is available for controlling secondary side synchronous rectification.The LT3752/LT3752-1 are available in a 38-lead plastic TSSOP package with missing pins for high voltage spacings.ApplicationsOffline and HV Car Battery Isolated Power Supplies48V Telecommunication Isolated Power SuppliesIndustrial, Automotive and Military Systems

The LT3753 is a current mode PWM controller optimized for an active clamp forward converter topology, allowing up to 100V input operation.A programmable volt-second clamp allows primary switch duty cycles above 50% for high switch, transformer and rectifier utilization. Active clamp control reduces switch voltage stress and increases efficiency. A synchronous output is available for controlling secondary side synchronous rectification.The LT3753 is available in a 38-lead plastic TSSOP package with missing pins for high voltage spacings.ApplicationsIndustrial, Automotive and Military Systems48V Telecommunication Isolated Power Supplies

The LT3754 is a 16-channel LED driver with a step-up DC/DC controller capable of driving up to 45V of LEDs. Each channel contains an accurate current sink with ±2.8% current matching. Channels follow a master programmable current to allow between 10mA to 50mA of LED current per string. Channels can be paralleled for higher LED current. Output voltage adapts to variations in LED VFfor optimum efficiency and open LED faults do not affect the operation of connected LED strings.The LT3754 allows a PWM dimming range up to 3000:1 and an analog dimming range up to 25:1. Operating frequency can be programmed from 100kHz up to 1MHz using a single resistor or synchronized to an external clock.Additional features include: programmable maximum VOUTfor open LED protection, a fault flag for open LED, programmable LED current derating vs temperature, micropower shutdown and internal soft-start. The LT3754 is available in a thermally enhanced 5mm × 5mm 32-pin QFN Package.ApplicationsAutomotive, Notebook and TV Monitor Backlighting

The LT3755, LT3755-1 and LT3755-2 are DC/DC controllers designed to operate as a constant-current source for driving high current LEDs. They drive a low side external N-channel power MOSFET from an internal regulated 7.15V supply. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. A ground referenced voltage FB pin serves as the input for several LED protection features, and also makes it possible for the converter to operate as a constant-voltage source. A frequency adjust pin allows the user to program the frequency from 100kHz to 1MHz to optimize efficiency, performance or external component size.The LT3755/LT3755-1/LT3755-2 sense output current at the high side of the LED string. High side current sensing is the most flexible scheme for driving LEDs, allowing boost, buck mode or buck-boost mode configuration. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides additional analog dimming capability.ApplicationsHigh Power LEDBattery ChargersAccurate Current Limited Voltage Regulators

The LT3756, LT3756-1 and LT3756-2 are DC/DC controllers designed to operate as a constant-current source for driving high current LEDs. They drive a low side external N-channel power MOSFET from an internal regulated 7.15V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. A ground referenced voltage FB pin serves as the input for several LED protection features, and also makes it possible for the converter to operate as a constant-voltage source. A frequency adjust pin allows the user to program the frequency from 100kHz to 1MHz to optimize efficiency, performance or external component size.The LT3756/LT3756-1/LT3756-2 sense output current at the high side of the LED string. High side current sensing is the most flexible scheme for driving LEDs, allowing boost, buck mode or buck-boost mode configuration. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL input provides additional analog dimming capability.ApplicationsHigh Power LED ApplicationsCurrent Limited Constant Voltage ApplicationsBattery Charging