Analog Devices

The LT3757/LT3757A are wide input range, current mode, DC/DC controllers which are capable of generating either positive or negative output voltages. They can be configured as either a boost, flyback, SEPIC or inverting converter. The LT3757/LT3757A drive a low side external N-channel power MOSFET from an internal regulated 7.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.The operating frequency of LT3757/LT3757A can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin. A low minimum operating supply voltage of 2.9V, and a low shutdown quiescent current of less than 1µA, make the LT3757/LT3757A ideally suited for battery-operated systems.The LT3757/LT3757A feature soft-start and frequency foldback functions to limit inductor current during startup and output short-circuit. The LT3757A has improved load transient performance compared to the LT3757.APPLICATIONSAutomotive and Industrial Boost, Flyback, SEPIC and Inverting ConvertersTelecom Power SuppliesPortable Electronic Equipment

The LT3758/LT3758A are wide input range, current mode, DC/DC controllers which are capable of generating either positive or negative output voltages. They can be configured as either a boost, flyback, SEPIC or inverting converter. The LT3758/LT3758A drive a low side external N-channel power MOSFET from an internal regulated 7.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.The operating frequency of LT3758/LT3758A can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin. A minimum operating supply voltage of 5.5V, and a low shutdown quiescent current of less than 1μA, make the LT3758/LT3758A ideally suited for batterypowered systems.The LT3758/LT3758A feature soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. The LT3758A has improved load transient performance compared to the LT3758.APPLICATIONSAutomotiveTelecomIndustrial

The LT3759 is a wide input range, current mode, DC/DC controller which is capable of regulating either positive or negative output voltages from a single feedback pin. It can be configured as a boost, SEPIC or inverting converter.The LT3759 drives a low side external N-channel power MOSFET. An internal LDO regulator draws power from VINor DRIVE to provide up to a 4.75V supply for the gate driver. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. The operating frequency of LT3759 can be set over a 100kHz to 1MHz range with an external resistor, or can be synchronized to an external clock using the SYNC pin.The LT3759 features soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. A window comparator on the FBX pin reports via thePGOODpin, providing output voltage status indication. The device is available in a 12-Lead exposed pad MSOP package.ApplicationsDatacom and Industrial Boost, SEPIC and Inverting ConvertersDistributed Power SuppliesPortable Electronic EquipmentAutomotive

The LT3761/LT3761-1 is a DC/DC controller designed to operate as a constant-current source and constant-voltage regulator. It features a programmable internal PWM dimming signal. The LT3761/LT3761-1 is ideally suited for driving high current LEDs, but also has features to make it suitable for charging batteries and supercapacitors. The fixed frequency, current mode architecture results in stable operation over a wide range of supply and output voltages. A voltage feedback 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 LT3761-1 can be synchronized to an external clock. The LT3761/LT3761-1 senses output current at the high side or at the low side of the load. The PWM input can be configured to self-oscillate at fixed frequency with duty ratio programmable from 4% to 96%. When driven by an external signal, the PWM input provides LED dimming ratios of up to 3000:1. The CTRL input provides additional analog dimming capability.The LT3761/LT3761-1 senses output current at the high side or at the low side of the load. The PWM input can be configured to self-oscillate at fixed frequency with duty ratio programmable from 4% to 96%. When driven by an external signal, the PWM input provides LED dimming ratios of up to 3000:1. The CTRL input provides additional analog dimming capability.NOTESLT3761AHigher PWM Dimming Accuracy at Lower LED Current LevelsLT3761-1Frequency SynchronizationLT3761Open LED Status PinApplicationsHigh Voltage LED Strings >100V with Ground Referred Current SenseGrounded Anode LEDsAccurate Current Limited Voltage Regulators

The LT3762 is a synchronous DC/DC controller designed to operate as a constant-current source and constant-voltage regulator. It features a programmable internal PWM dimming signal generator and a synchronous gate driver. The LT3762 is ideally suited for driving high current LEDs with high efficiency and reduced power loss. Rail-to-rail switch current sensing enables synchronous boost topologies and nonsynchronous topologies such as SEPIC. A voltage feedback pin serves as the input for several LED protection features and also allows 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 and external component size. Adding a capacitor at SSFM pin activates the Spread-Spectrum Modulation feature to reduce EMI. The LT3762 also includes an integrated DC/DC converter to efficiently produce a regulated 7.5V supply for the N-channel MOSFET gate drivers. The PWM pin controls PWMTG to drive the P-channel MOSFET, allowing a high PWM dimming range (3000:1) and providing LED overcurrent protection and short-circuit protected boost capability.ApplicationsIndustrial and Automotive LightingAccurate Current-Limited Voltage Regulators

The LT3763 is a fixed frequency, synchronous, step-down DC/DC controller designed to accurately regulate output currents up to 20A. The average current mode controller will maintain inductor current regulation over a wide output voltage range from 0V to 55V. Output current is set by analog voltages on the CTRL pins and an external sense resistor. Voltage regulation and overvoltage protection are set with a voltage divider from the output to the FB pin. The switching frequency is programmable from 200kHz to 1MHz through an external resistor on the RT pin or with the SYNC pin and an external clock signal. Input and output current sensing provides input current limiting and an accurate measurement of these currents. The FBIN pin is provided for applications requiring a peak power tracking function.Additional features include an accurate external reference voltage for use with the CTRL pins, an accurate UVLO/EN pin that allows for programmable UVLO hysteresis, a PWM driver for LED applications, output voltage fault detection, and thermal shutdown.ApplicationsHigh Power Architectural LightingAutomotive LightingAviation and Marine Strobe LightsSolar-Powered Chargers, Laser Diodes

The LT3781 controller simplifies the design of high power synchronous dual transistor forward DC/DC converters. The part employs fixed frequency current mode control and supports both isolated and nonisolated topologies. The IC drives external N-channel power MOSFETs and operates with input voltages up to 72V.The LT3781 is ideal for output derived power schemes, through the use of a large undervoltage lockout hysteresis range. The part is also equipped with an 18V VCCshunt regulator, which prevents exceeding absolute maximum ratings while in trickle start applications.The LT3781’s operating frequency is programmable and can be synchronized up to 350kHz. Switch phase is also controlled during synchronized operation to accommodate multiple-converter systems. Internal logic guarantees 50% maximum duty cycle operation to prevent transformer saturation.The LT3781 is available in a 20-lead SSOP package.ApplicationsIsolated Telecommunication SystemsPersonal Computers and PeripheralsDistributed Power Step-Down ConvertersLead Acid Battery Backup SystemsAutomotive and Heavy Equipment

The LT3782A is a current mode 2-phase step-up DC/DC converter controller. Its high switching frequency (up to 500kHz) and 2-phase operation reduce system filtering capacitance and inductance requirements.With 10V gate drive (VCC≥13V) and 4A peak drive current, the LT3782A can drive most industrial grade high power MOSFETs with high efficiency. For synchronous applications, the LT3782A provides synchronous gate signals with programmable falling edge delay to avoid cross conduction when using external MOSFET drivers. Other features include programmable undervoltage lockout, soft-start, current limit, duty cycle clamp (50% or higher) and slope compensation. The LT3782A is identical to the LT3782 except that the LT3782A has a tighter current sense mismatch tolerance.The LT3782A is available in thermally enhanced 28-lead TSSOP and 4mm × 5mm QFN packages.ApplicationsIndustrial EquipmentTelecom InfrastructureInterleaved Isolated Power Supply

The LT3790 is a synchronous 4-switch buck-boost voltage/current regulator controller. The LT3790 can regulate output voltage, output current, or input current with input voltages above, below, or equal to the output voltage. The constant-frequency, current mode architecture allows its frequency to be adjusted or synchronized from 200kHz to 700kHz. No top FET refresh switching cycle is needed in buck or boost operation. With 60V input, 60V output capability and seamless transitions between operating regions, the LT3790 is ideal for voltage regulator, battery/super-capacitor charger applications in automotive, industrial, telecom, and even battery-powered systems.The LT3790 provides input current monitor, output current monitor, and various status flags, such as C/10 charge termination and shorted output flag.APPLICATIONSAutomotive, Telecom, Industrial SystemsHigh Power Battery-Powered System