Analog Devices Inc./Maxim Integrated

The LTC3897 is a synchronous boost DC/DC controller with surge stopper and ideal diode controller.The boost controller drives two N-channel power MOSFET stages out-of-phase to reduce input and output capacitor requirements, allowing the use of smaller inductors than the single-phase equivalent. Synchronous rectification reduces power loss and eases thermal requirements.The surge stopper controls the gate of an external N-channel MOSFET to protect against high voltage input transients and provides in-rush current control, overcurrent protection and output disconnect for the boost converter. The integrated ideal diode controller drives another N-channel MOSFET to replace a Schottky diode for reverse input protection and voltage holdup or peak detection. It controls the forward voltage drop across the MOSFET and minimizes reverse current flow.The LTC3897 is available in thermally-enhanced 38-pin leadless QFN or 38-lead TSSOP packages.ApplicationsIndustrialAutomotiveMilitary/Avionics

The LTC3897-2 is a synchronous boost DC/DC controller with surge stopper and ideal diode controller.The boost controller drives two N-channel power MOSFET stages out-of-phase to reduce input and output capacitor requirements, allowing the use of smaller inductors than the single-phase equivalent. Synchronous rectification reduces power loss and eases thermal requirements.The surge stopper controls the gate of an external N-channel MOSFET to protect against high voltage input transients and provides inrush current control, overcurrent protection and output disconnect for the boost converter. The integrated ideal diode controller drives another N-channel MOSFET to replace a Schottky diode for reverse input protection and voltage holdup or peak detection. It controls the forward voltage drop across the MOSFET and minimizes reverse current flow.The differences between the LTC3897-2 and LTC3897 are shown in Table 1.ApplicationsIndustrialAutomotiveMilitary/AvionicsTelecommunications

The LTC3899 is a high performance triple output (buck/ buck/boost) DC/DC switching regulator controller that drives all N-channel synchronous power MOSFET stages. The constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz. The LTC3899 operates from a wide 4.5V to 60V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC3899 can operate from an input supply as low as 2.2V after start-up.The gate drive for the LTC3899 can be programmed from 5V to 10V to allow the use of logic-level or standard-level FETs and to maximize efficiency. Internal switches in the top gate drivers eliminate the need for external bootstrap diodes. The 29μA no-load quiescent current extends operating run time in battery-powered systems. OPTI-LOOP®compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values.APPLICATIONSAutomotive Always-On and Start-Stop SystemsDistributed DC Power SystemsMultioutput Buck-Boost Applications

The LTC3900 is a secondary-side synchronous rectifier driver designed to be used in isolated forward converter power supplies. The chip drives N-channel rectifier MOSFETs and accepts pulse sychronization from the primary-side controller via a pulse transformer.The LTC3900 incorporates a full range of protection for the external MOSFETs. A programmable timeout function is included that disables both drivers when the synchronization signal is missing or incorrect. Additionally, the chip senses the output inductor current through the drainsource resistance of the catch MOSFET, shutting off the MOSFET if the inductor current reverses. The LTC3900 also shuts off the drivers if the supply voltage is too low.Applications48V Input Isolated DC/DC ConvertersIsolated Telecom Power SuppliesHigh Voltage Distributed PowerStep-Down ConvertersIndustrial Control System Power SuppliesAutomotive and Heavy Equipment

The LTC4000 is a high voltage, high performance controller that converts many externally compensated DC/DC power supplies into full-featured battery chargers.Features of the LTC4000’s battery charger include: accurate (±0.25%) programmable float voltage, selectable timer or current termination, temperature qualified charging using an NTC thermistor, automatic recharge, C/10 trickle charge for deeply discharged cells, bad battery detection and status indicator outputs. The battery charger also includes precision current sensing that allows lower sense voltages for high current applications.The LTC4000 supports intelligent PowerPath control. An external PFET provides low loss reverse current protection. Another external PFET provides low loss charging or discharging of the battery. This second PFET also facilitates an instant-on feature that provides immediate downstream system power even when connected to a heavily discharged or short faulted battery.The LTC4000 is available in a low profile 28-lead 4mm × 5mm QFN and SSOP packages.LTC4000LTC4000-1Input Voltage Regulation MPPCNoYesInput Current MonitoringYesYesInput Current RegulationYesNoApplicationsHigh Power Battery Charger SystemsHigh Performance Portable InstrumentsIndustrial Battery Equipped DevicesNotebook/Subnotebook Computers

The LTC4000-1 is a high voltage, high performance controller that converts many externally compensated DC/DC power supplies into full-featured battery chargers with maximum power point control. In contrast to the LTC4000, the LTC4000-1 has an input voltage regulation loop instead of the input current regulation loop.Features of the LTC4000-1’s battery charger include: accurate (±0.25%) programmable float voltage, selectable timer or current termination, temperature qualified charging using an NTC thermistor, automatic recharge, C/10 trickle charge for deeply discharged cells, bad battery detection and status indicator outputs. The battery charger also includes precision current sensing that allows lower sense voltages for high current applications.The LTC4000-1 supports intelligent PowerPath control. An external PFET provides low loss reverse current protection. Another external PFET provides low loss charging or discharging of the battery. This second PFET also facilitates an instant-on feature that provides immediate downstream system power even when connected to a heavily discharged or shorted battery.The LTC4000-1 is available in a low profile 28-lead 4mm × 5mm QFN and SSOP packages.LTC4000LTC4000-1Input Voltage Regulation MPPCNoYesInput Current MonitoringYesYesInput Current RegulationYesNoApplicationsSolar Powered Battery Charger SystemsBattery Charger with High Impedance Input Source, e.g., Fuel Cell or Wind TurbineBattery Equipped Industrial or Portable Military Equipments

The LTC4001-1 is a 2A Li-Ion battery charger intended for 5V wall adapters. It utilizes a 1.5MHz synchronous buck converter topology to reduce power dissipation during charging. Low power dissipation, an internal MOSFET and sense resistor allow a physically small charger that can be embedded in a wide range of handheld applications. The LTC4001-1 includes complete charge termination circuitry, automatic recharge and a ±1% 4.1V float voltage. Input short-circuit protection is included so no blocking diode is required.This 4.1V version of the standard LTC4001 is intended for applications which will be operated or stored above approximately 60°C. Under these conditions, the reduced float voltage will trade-off initial cell capacity for the benefit of increased capacity retention over the life of the battery. A reduced float voltage also minimizes swelling in prismatic and polymer cells, and avoids open CID (pressure fuse) in cylindrical cells.Battery charge current, charge timeout and end-of-charge indication parameters are set with external components. Additional features include shorted cell detection, temperature qualified charging and overvoltage protection. The LTC4001-1 is available in a low profile (0.75mm) 16-lead (4mm × 4mm) QFN package.Float VoltageLTC40014.2VLTC4001-14.1VApplicationsHandheld Battery-Powered DevicesHandheld ComputersCharging Docks and CradlesDigital CamerasSmart Phones

The LTC4002 is a complete battery charger controller for one (4.2V) or two (8.4V) cell lithium-ion batteries. With a 500kHz switching frequency, the LTC4002 provides a small, simple and efficient solution to fast charge Li-Ion batteries from a wide range of supply voltages. An external sense resistor sets the charge current with ±5% accuracy. An internal resistor divider and precision reference set the final float voltage to 4.2V per cell with ±1% accuracy.When the input supply is removed, the LTC4002 automatically enters a low current sleep mode, dropping the battery drain current to 10µA. An internal comparator detects the near end-of-charge condition while an internal timer sets the total charge time and terminates the charge cycle. After the charge cycle ends, if the battery voltage drops below 4.05V per cell, a new charge cycle will automatically begin.The LTC4002 is available in the 8-lead SO and 10-lead DFN packages.ApplicationsPortable ComputersCharging DocksHandheld Instruments