Analog Devices Inc./Maxim Integrated

The LT3503 is a current mode PWM step-down DC/DC converter with an internal 1.45A power switch. The wide operating input range of 3.6V to 20V makes the LT3503 ideal for regulating power from a wide variety of sources. Its high operating frequency allows the use of tiny, low cost inductors and ceramic capacitors, resulting in low, predictable output ripple.Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up. The low current (<2µA) shutdown mode provides output disconnect, enabling easy power management in battery-powered systems.ApplicationsAutomotive Battery RegulationIndustrial Control SuppliesWall Transformer RegulationDistributed Supply RegulationBattery-Powered Equipment

The LT3504 consists of four 1A output current buck regulators. The LT3504 has a wide operating input range of 3.2V to 40V. An on-chip boost regulator allows each channel to operate up to 100% duty cycle and eliminates the need for four external charge pump circuits. The LT3504 is designed to minimize external component count and results in a simple and small application circuit.The LT3504 operates robustly in fault conditions. Cycle-by-cycle peak current limit and catch diode current limit sensing protect the part during overload conditions. Thermal shutdown protects the power switches at elevated temperatures. Soft-start helps keep the peak inductor current under control during startup.The LT3504 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.ApplicationsAutomotive Battery RegulationIndustrial Control SuppliesWall Transformer RegulationDistributed Supply Regulation

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