Analog Devices Inc./Maxim Integrated

The LT3684 is an adjustable frequency (300kHz to 2.8MHz) monolithic buck switching regulator that accepts input voltages up to 34V (36V maximum). A high efficiency 0.18Ω switch is included on the die along with a boost Schottky diode and the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability. The LT3684’s high operating frequency allows the use of small, low cost inductors and ceramic capacitors resulting in low output ripple while keeping total solution size to a minimum. The low current shutdown mode 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). A power good flag signals when VOUTreaches 90% of the programmed output voltage. The LT3684 is available in 10-Pin MSOP and 3mm × 3mm DFN packages with Exposed Pads for low thermal resistance.ApplicationsAutomotive Battery RegulationPower for Portable ProductsDistributed Supply RegulationIndustrial SuppliesWall Transformer Regulation

The LT3685 is an adjustable frequency (200kHz to 2.4MHz) monolithic step-down switching regulator that accepts input voltages up to 38V operating and 60V maximum. An internal overvoltage protection circuit turns off the power switch when VINis above 38V typical (36V minimum) which then allows the part to safely withstand 60V transients. A high efficiency 0.25Ω switch is included on the die along with a boost Schottky diode and the necessary oscillator, control, and logic circuitry. Current mode topology is used for fast transient response and good loop stability. The LT3685’s high operating frequency allows the use of small, low cost inductors and ceramic capacitors resulting in low output ripple while keeping total solution size to a minimum. The low current shutdown mode 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). A power good flag signals when VOUTreaches 89% of the programmed output voltage. The LT3685 is available in 10-Pin MSOP and 3mm × 3mm DFN packages with exposed pads for low thermal resistance.ApplicationsAutomotive Battery RegulationSet Top BoxDistributed Supply RegulationIndustrial SuppliesWall Transformer Regulation

The LT3689 is an adjustable frequency (350kHz to 2.2MHz) monolithic step-down switching regulator with a power-on reset and watchdog timer. The regulator operates from inputs up to 36V and withstands transients up to 60V. Low ripple Burst Mode®operation maintains high efficiency at low output current while keeping output ripple below 15mV in a typical application, with input quiescent current of just 85μA. Shutdown circuitry reduces input supply current to less than 1μA while EN/UVLO is pulled low. Using a resistor divider on the EN/UVLO pin provides a programmable undervoltage lockout. Current limit, frequency foldback and thermal shutdown provide fault protection.The reset and watchdog timeout periods are independently adjustable using external capacitors. Tight accuracy specifications and glitch immunity ensure reliable reset operation of a system without false triggering. The open collectorRSTwill pull down if output voltage drops 10% below the programmed value. The watchdog timer is pin-selectable for window or timeout modes. In timeout mode,WDOpulls low if too long of a period passes before a watchdog transition is detected. In window mode, the LT3689 monitors for WDI falling edges grouped too close together or too far apart.ApplicationsAutomotive Electronic Control UnitsIndustrial Power Supplies

The LT3693 is an adjustable frequency (200kHz to 2.4MHz) monolithic buck switching regulator that accepts input voltages up to 36V. A high efficiency 95mΩ switch is included on the die along with a boost Schottky diode and the necessary oscillator, control, and logic circuitry. Current mode topology is used for fast transient response and good loop stability. 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). A power good flag signals when VOUTreaches 91% of the programmed output voltage. The LT3693 is available in 10-Pin MSOP and 3mm × 3mm DFN packages with exposed pads for low thermal resistance.ApplicationsAutomotive Battery RegulationPower for Portable ProductsDistributed Supply RegulationIndustrial SuppliesWall Transformer Regulation