Analog Devices

The LT3507 is a triple, current mode, DC/DC converter with internal power switches and a low dropout regulator. The switching converters are step-down converters capable of generating one 2.4A output and two 1.5A outputs. All three converters are synchronized to a single oscillator. The 2.4A output runs with opposite phase to the other two converters, reducing input ripple current. Each regulator has independent shutdown and soft-start circuits, and generates a power good signal when its output is in regulation, easing power supply sequencing and interfacing with microcontrollers and DSPs.The switching frequency is set with a single resistor yielding a range of 250kHz to 2.5MHz. The high switching frequency allows the use of small inductors and capacitors resulting in a very small triple output supply. The constant switching frequency, combined with low impedance ceramic capacitors, results in low, predictable output ripple. With its wide input voltage range of 4V to 36V, the LT3507 regulates a broad array of power sources including 5V logic rails, unregulated wall transformers, lead acid batteries and distributed power supplies.Output CurrentPackageLT35072.5A, 1.5A, 1.5A5 × 7 QFN-38LT3507A2.7A, 1.8A, 1.8A5 × 7 QFN-38, TSSOP-38EApplicationsDSL and Cable ModemsDistributed Power RegulationDSP PowerAutomotive

The LT3508 is a dual current mode PWM step-down DC/DC converter with internal power switches capable of generating two 1.4A outputs. The wide input voltage range of 3.7V to 36V makes the LT3508 suitable for regulating power from a wide variety of sources, including automotive batteries, 24V industrial supplies and unregulated wall adapters. Both converters are synchronized to a single oscillator programmable up to 2.5MHz and run with opposite phases, reducing input ripple current. Its high operating frequency allows the use of small, low cost inductors and ceramic capacitors, resulting in low, predictable output ripple. Each regulator has independent tracking and soft-start circuits and generates a power good signal when its output is in regulation, easing power supply sequencing and interfacing with microcontrollers and DSPs.Cycle-by-cycle current limit, frequency foldback and thermal shutdown provide protection against shorted outputs, and soft-start eliminates input current surge during startup. The low current (<2µA) shutdown mode enables easy power management in battery-powered systems.ApplicationsAutomotiveDSP Power SuppliesWall Transformer RegulationDSL and Cable ModemsPCI Express

The LT3509 is a dual, current mode, step-down switching regulator, with internal power switches each capable of providing 700mA output current. This regulator provides a compact and robust solution for multi-rail systems in harsh environments. It incorporates several protection features including overvoltage lockout and cycle-by-cycle current limit. Thermal shutdown provides additional protection. The loop compensation components and the boost diodes are integrated on-chip. Switching frequency is set by a single external resistor. External synchronization is also possible. The high maximum switching frequency allows the use of small inductors and ceramic capacitors for low ripple. Constant frequency operation above the AM band avoids interference with radio reception, making the LT3509 well suited for automotive applications. Each regulator has an independent shutdown and soft-start control pin. When both converters are powered down, the common circuitry enters a low current shutdown state.ApplicationsAutomotive ElectronicsIndustrial ControlsWall Transformer RegulationNetworking DevicesCPU, DSP, or FPGA Power

The LT3510 is a dual current mode PWM step-down DC/DC converter with two internal 2.5A switches. Independent input voltage, feedback, soft-start and power good pins for each channel simplify complex power supply tracking/sequencing requirements.Both converters are synchronized to either a common external clock input or a resistor programmable fixed 250kHz to 1.5MHz internal oscillator. At all frequencies, a 180° phase relationship between channels is maintained, reducing voltage ripple and component size. Programmable frequency allows for optimization between efficiency and external component size.Minimum input-to-output voltage ratios are improved by allowing the switch to stay on through multiple clock cycles, only switching off when the boost capacitor needs recharging, resulting in ~95% maximum duty cycle.Each output can be independently disabled using its own soft-start pin, or by using the SHDN pin the entire part can be placed in a low quiescent current shutdown mode.The LT3510 is available in a 20-lead TSSOP package with exposed leadframe for low thermal resistance.ApplicationsDSP Power SuppliesDisc DrivesDSL/Cable ModemsWall Transformer RegulationDistributed Power RegulationPCI Cards

The LT3511 is a high voltage monolithic switching regulator specifically designed for the isolated flyback topology. No third winding or opto-isolator is required for regulation as the part senses output voltage directly from the primary-side flyback waveform. The device integrates a 240mA, 150V power switch, high voltage circuitry, and control into a high voltage 16-lead MSOP package with four leads removed.The LT3511 operates from an input voltage range of 4.5V to 100V and delivers up to 2.5W of isolated output power. Two external resistors and the transformer turns ratio easily set the output voltage. Off-the-shelf transformers are available for several applications. The high level of integration and the use of boundary mode operation results in a simple, clean, tightly regulated application solution to the traditionally tough problem of isolated power delivery.ApplicationsIsolated Telecom Power SuppliesIsolated Auxiliary/Housekeeping Power SuppliesIsolated Industrial, Automotive and Medical Power Supplies

The LT3512 is a high voltage monolithic switching regulator specifically designed for the isolated flyback topology. No third winding or opto-isolator is required for regulation as the part senses output voltage directly from the primary-side flyback waveform. The device integrates a 420mA, 150V power switch, high voltage circuitry, and control into a high voltage 16-lead MSOP package with four leads removed.The LT3512 operates from an input voltage range of 4.5V to 100V and delivers up to 4.5W of isolated output power. Two external resistors and the transformer turns ratio easily set the output voltage. Off-the-shelf transformers are available for several applications. The high level of integration and the use of boundary mode operation results in a simple, clean, tightly regulated application solution to the traditionally tough problem of isolated power delivery.ApplicationsIsolated Telecom Power SuppliesIsolated Auxiliary/Housekeeping Power SuppliesIsolated Industrial, Automotive and Medical Power Supplies

The LT3513 5-output adjustable switching regulator provides power for large TFT-LCD panels. The 38-pin 5mm × 7mm QFN device can generate a 3.3V or 5V logic supply along with the triple output supply required for the TFT-LCD panel. A lower voltage secondary logic supply may also be generated with the addition of an external NPN driven by the internal linear regulator. A step-down regulator provides a low voltage output, VLOGIC, with up to 1.2A of current while capable of operating from a wide input range of 4.5V to 30V. A high power step-up converter, a lower power step-up converter and an inverting converter provide the three independent output voltages: AVDD, VONand VOFFrequired by the LCD panel. A high-side PNP provides delayed turn-on of the VONsignal and can handle up to 30mA. Protection circuitry ensures that VONis disabled if any of the four outputs are more than 10% below the programmed voltage.ApplicationsAutomotive TFT-LCD DisplaysLarge TFT-LCD Desktop MonitorsFlat Panel Televisions

The LT3514 consists of three buck regulators (2A, 1A, 1A output current). The device has a wide operating input range of 3.2V to 36V. An on-chip boost regulator allows each channel to operate up to 100% duty cycle. The LT3514 is designed to minimize external component count and results in a simple and small application circuit.The LT3514 operates robustly in fault conditions. Cycleby- cycle peak current limit and catch diode current limit sensing protect the IC during overload conditions. Thermal shutdown protects the power switches at elevated temperatures. Soft-start helps control the peak inductor current during startup.The LT3514 also features output voltage tracking and sequencing, programmable frequency, programmable undervoltage lockout, and a power good pin to indicate when all outputs are in regulation.The LT3514 has one fewer channel (CH2) than the LT3504, and has one channel (CH3) that outputs 2A instead of 1A. The LT3514 in QFN is pin compatible with the LT3504. The LT3504 provides four 1A outputs.ApplicationsAutomotive Battery RegulationIndustrial Control SuppliesWall Transformer RegulationDistributed Supply Regulation

The LT3517 is a current mode DC/DC converter with an internal 1.5A, 45V switch specifically designed to drive LEDs. The LT3517 operates as a LED driver in boost, buck mode and buck-boost mode. It combines a traditional voltage loop and a unique current loop to operate as a constant-current source or constant-voltage source. Programmable switching frequency allows optimization of the external components for efficiency or component size. The switching frequency of LT3517 can be synchronized to an external clock signal. The LED current is externally programmable with a 100mV sense resistor. The external PWM input provides up to 5000:1 LED dimming. The CTRL pin provides further 10:1 dimming ratio.The LT3517 is available in the tiny footprint 16-lead QFN (4mm × 4mm) and the 16-pin TSSOP packages. The LT3517 provides a complete solution for both constant-voltage and constant-current applications.ApplicationsDisplay BacklightingAutomotive and Avionic LightingIlluminationScanners

The LT3518 is a current mode DC/DC converter with an internal 2.3A, 45V switch specifically designed to drive LEDs. The LT3518 operates as a LED driver in boost, buck mode and buck-boost mode. It combines a traditional voltage loop and a unique current loop to operate as a constant-current source or constant-voltage source. Programmable switching frequency allows optimization of the external components for efficiency or component size. The switching frequency of the LT3518 can be synchronized to an external clock signal. The LED current is externally programmable with a 100mV sense resistor. The external PWM input provides 3000:1 LED dimming. The CTRL pin provides further 10:1 dimming ratio.The LT3518 is available in the tiny footprint 16-lead QFN (4mm × 4mm) and the 16-pin TSSOP package. The LT3518 provides a complete solution for both constant-voltage and constant-current applications.ApplicationsDisplay BacklightingAutomotive and Avionic LightingIlluminationScanners