Analog Devices Inc./Maxim Integrated

The LT3694/LT3694-1 are monolithic, current mode DC/DC converters with dual, low dropout regulator controllers. The switching converter is a step-down converter capable of generating up to 2.6A at its output. Each regulator has independent track/soft-start circuits simplifying power supply sequencing and interfacing with microcontrollers and DSPs.The switching frequency is set with a single resistor with a range of 250kHz to 2.5MHz. The high switching frequency permits the use of small inductors and ceramic capacitors leading to very small triple output solutions. The constant-switching frequency, combined with low impedance ceramic capacitors, results in low, predictable output ripple. Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3694 against short-circuit conditions. Frequency foldback and thermal shutdown provide additional protection.With its wide input voltage range of 4V to 36V, the LT3694 regulates a broad array of power sources from 4-cell batteries and 5V logic rails to unregulated wall transformers, lead acid batteries and distributed power supplies. The LT3694 can be synchronized to an external clock with the SYNC pin while the LT3694-1 offers a CLKOUT pin allowing other DC/DC converters to synchronize to the LT3694-1 clock.ApplicationsAutomotiveIndustrialDSL and Cable ModemsDistributed Power RegulationWall Transformer Regulation

The LT3695 series are adjustable frequency (250kHz to 2.2MHz) monolithic buck switching regulators that accept input voltages up to 36V and can safely sustain transient voltages up to 60V. The devices include a high efficiency switch, a boost diode, and the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability. A SYNC pin allows the user to synchronize the part to an external clock, and to choose between low ripple Burst Mode operation and standard PWM operation.The LT3695 regulators tolerate adjacent pin shorts or an open pin without raising the output voltage above its programmed value.Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV in a typical application. Shutdown reduces input supply current to less than 1μA while a resistor and capacitor on the RUN/SS pin provide a controlled output voltage ramp (soft-start). Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3695 regulators against short-circuit conditions. Frequency foldback and thermal shutdown provide additional protection.The LT3695 series is available in a thermally enhanced 16-pin MSOP package.ApplicationsAutomotive Battery RegulationAutomotive Entertainment SystemsDistributed Supply RegulationIndustrial Supplies

The LT3697 is a 35V, 2.5A step-down switching regulator designed to power 5V USB applications. A precise output voltage and programmable cable drop compensation maintain accurate 5V regulation at the USB socket connected to the end of a long cable. The accurate, programmable current limit can eliminate the need for a USB power switch and improve system reliability. The provided 180mA active load reduces output overshoot during load transients. Dual feedback allows regulation on the output of a USB switch and limits cable drop compensation to a maximum of 6.1V output, protecting USB devices during fault conditions. A separate 5V output can be taken from the SYS terminal to power auxiliary circuitry such as a USB hub controller. The LT3697 also provides a load current monitor output and an overcurrent fault indicator.The LT3697 operates from 300kHz to 2.2MHz and withstands input voltage transients up to 60V. The device's output survives shorts to ground and to the battery. A current mode topology is used for fast transient response and good loop stability. Shutdown reduces input supply current to less than 1μA. The LT3697 is available in a 16-lead MSOP package with an exposed pad for low thermal resistance.ApplicationsAutomotive USBIndustrial USB

The LT3710 is a high efficiency step-down switching regulator intended for auxiliary outputs in single secondary winding, multiple output power supplies.The LT3710 drives dual synchronous N-channel MOSFETs and achieves high efficiency. With leading edge modulation, it operates well with either primary side peak current or voltage mode control. It is synchronized to the falling edge of the transformer secondary winding and can be used in both single-ended and double-ended isolated power converter topologies. A high speed operational amplifier is incorporated to achieve optimum compensation and fast transient response. A user selectable discontinuous conduction mode improves light load efficiency.The LT3710 is available in a thermally enhanced TSSOP-16 exposed pad power package.Applications48V Isolated DC/DC ConvertersMultiple Output SuppliesOffline Converters

The LT3743 is a fixed frequency synchronous step-down DC/DC controller designed to drive high current LEDs. The average current mode controller will maintain inductor current regulation over a wide output voltage range of 0V to (VIN– 2V). LED dimming is achieved through analog dimming on the CTRL_L, CTRL_H and CTRL_T pins and with PWM dimming on the PWM and CTRL_SEL pins. Through the use of externally switched load capacitors, the LT3743 is capable of changing regulated LED current levels within several μs, providing accurate, high speed PWM dimming between two current levels. The switching frequency is programmable from 200kHz to 1MHz through an external resistor on the RT pin.Additional features include voltage regulation and overvoltage protection set with a voltage divider from the output to the FB pin. Overcurrent protection is provided and set by the CTRL_H pin.ApplicationsDLP ProjectorsHigh Power Architectural LightingLaser Diodes