Analog Devices

The LTC4417 connects one of three valid power supplies to a common output based on priority. Priority is defined by pin assignment, with V1 assigned the highest priority and V3 the lowest priority. A power supply is defined as valid when its voltage has been within its overvoltage (OV) and undervoltage (UV) window continuously for at least 256ms. If the highest priority valid input falls out of the OV/UV window, the channel is immediately disconnected and the next highest priority valid input is connected to the common output. Two or more LTC4417s can be cascaded to provide switchover between more than three inputs.The LTC4417 incorporates fast non-overlap switching circuitry to prevent both reverse and cross conduction while minimizing output droop. The gate driver includes a 6V clamp to protect external MOSFETs. A controlled output ramp feature minimizes start-up inrush current. Open drainVALIDoutputs indicate the input supplies have been within their OV/UV window for 256ms.APPLICATIONSIndustrial Handheld InstrumentsHigh Availability SystemsBattery Backup SystemsServers and Computer Peripherals

The LTC4418 connects one of two valid power supplies to a common output based on priority and validity. Priority is defined by pin assignment, with V1 assigned the higher priority and V2 the lower priority. A power supply is defined as valid when its voltage has been within its overvoltage (OV) and undervoltage (UV) window continuously for at least the configured validation time. If the highest priority valid input falls out of the OV/UV window, the channel is immediately disconnected and the other valid input is connected to the common output. Multiple LTC4418s, as well as triple channel LTC4417s, can be cascaded to provide switchover between more than two inputs.The LTC4418 incorporates fast non-overlap switching circuitry to prevent both reverse and cross conduction while minimizing output droop. The gate driver includes a 6V clamp to protect external MOSFETs. A controlled soft-start feature minimizes start-up inrush current. Open drainVALIDoutputs indicate the input supplies have been within their OV/UV window for the duration of the validation time. The validation time can be disabled or adjusted using an external capacitorApplicationsIndustrial Handheld InstrumentsHigh Availability SystemsBattery Backup SystemsServers and Computer Peripherals

The LTC4419 is a dual input monolithic PowerPath™prioritizer with low operating current, that provides backup switchover for keeping critical circuitry alive during brown out and power loss conditions. Unlike diode-OR products, little current is drawn from the inactive supply even if its voltage is greater than the active supply.Internal 2Ω, current limited PMOS switches provide power path selection from a primary input (V1) or a backup input (V2) to the output. An adjustable voltage monitor set via an external resistive divider provides flexibility in setting the V1 to V2 switchover threshold. When primary input V1 drops, the ADJ monitor input causes OUT to be switched to V2. Fast non-overlap switchover circuitry prevents both reverse and cross conduction while minimizing output droop.The LTC4419 has two auxiliary comparators with open-drain outputs that provide flexible voltage monitoring. The V2ON output indicates if V2 is powering OUT. Freshness seal mode prevents V2 battery discharge during storage or shipment.ApplicationsLow Power Battery BackupPortable EquipmentPoint-of-Sale (POS) Equipment

The LTC4420 is a dual input monolithic PowerPath™prioritizer, with low operating current, that provides backup switchover for keeping critical circuitry alive during brownout and power loss conditions. Unlike diode-OR products, little current is drawn from the inactive supply even if its voltage is greater than the active supply.Internal 2Ω, current limited PMOS switches provide power path selection from a primary input (V1) or a backup input (V2) to the output. Two adjustable voltage monitors set via external resistive dividers provide flexibility in setting V1 to V2 switchover and V2 undervoltage thresholds. V1 is monitored continuously while V2 supply monitoring includes controllable low duty cycle UV monitoring. When primary input V1 drops, the ADJ monitor causes OUT to be switched to V2. When V2 drops, it is disconnected from OUT ifV2DISis low. Fast non-overlap switchover circuitry prevents reverse and cross conduction while minimizing output droop.Auxiliary voltage monitor CMP1 provides flexible voltage monitoring and output V2OK provides V2 undervoltage status. Freshness seal mode prevents V2 battery discharge during storage or shipment.ApplicationsLow Power Battery BackupPortable EquipmentPoint-of-Sale (POS) Equipment

The LTC4421 connects one of two input supplies to a common output based on user-defined priority and validity. By definition, the supply connected to V1 is the higher priority supply, although this can be changed dynamically. External resistive dividers set the undervoltage and overvoltage thresholds that bound the valid voltage window.Strong gate drivers switch the large external N-channel MOSFETs quickly. Fast switchover circuitry minimizes output droop when changing channels while preventing reverse and cross conduction. A fast comparator detects input short circuits and quickly turns off the N-channel MOSFETs to minimize disruption.External sense resistors set the maximum inrush and current limit currents. During current limiting, the LTC4421 controls the N-channel MOSFET gate to regulate 25mV across the sense resistor. When the sense resistor voltage has been regulated to 25mV for a user-settable time, the channel is disconnected and a fault is set.ApplicationsHigh Reliability SystemsServer Based Back-Up SystemsIndustrial Handheld InstrumentsBattery Back-Up Systems

The LTC4425 is a constant-current/constant-voltage linear charger designed to charge a 2-cell supercap stack from either a Li-Ion/Polymer battery, a USB port, or a 2.7V to 5.5V current-limited supply. The part operates as an ideal diode with an extremely low 50mΩ on-resistance making it suitable for high peak-power/low average power applications. The LTC4425 charges the output capacitors to an externally programmed output voltage in LDO mode at a constant charge current, or to VINin normal mode with a smart charge current profile to limit the inrush current until the VINto VOUTdifferential is less than 250mV. In addition the LTC4425 can be set to clamp the output voltage to 4.9V or 5.4V.Charge current (VOUTcurrent limit) is programmed by connecting a resistor between PROG and GND. The voltage on the PROG pin represents the current fl owing from VINto VOUTfor current monitoring. An internal active balancing circuit maintains equal voltages across each supercapacitor and clamps the peak voltage across each cell to a pin-selectable maximum value. The LTC4425 operates at a very low 20μA quiescent current (shutdown current <3μA) and is available in a low profile 12-pin 3mm × 3mm DFN or a 12-lead MSOP package.ApplicationsHigh Peak Power Battery/USB Powered EquipmentIndustrial PDAsPortable Instruments/Monitoring EquipmentPower Meters, SuperCap Backup CircuitsPC Card/USB Modems

The LTC4440A-5 is a high frequency high side N-channel MOSFET gate driver that is designed to operate in applications with VINvoltages up to 80V. The LTC4440A-5 can also withstand and continue to function during 100V VINtransients. The powerful driver capability reduces switching losses in MOSFETs with high gate capacitances. The LTC4440A-5’s pull-up has a peak output current of 1.1A and its pull-down has an output impedance of 1.85Ω.The LTC4440A-5 features supply independent TTL/CMOS compatible input thresholds with 350mV of hysteresis. The input logic signal is internally level-shifted to the bootstrapped supply, which may function at up to 95V above ground.The LTC4440A-5 is optimized for driving (5V) logic level FETs and contains an undervoltage lockout circuit that disables the external MOSFET when activated.The LTC4440A-5 is available in the thermally enhanced 8-lead MSOP package.ParameterLTC4440A-5LTC4440-5LTC4440Max Operating TS80V60V80VAbssolute Max TS100V80V100VMOSFET Gate Drive4V to 15V4V to 15V8V to 15VVCCUV+3.23.26.3VCCUV–3.04V3.04V6.0VApplicationsAutomotive Power SystemsTelecommunications Power SystemsDistributed Power ArchitecturesServer Power SuppliesHigh Density Power ModulesGeneral Purpose Low or High Side Driver

The LTC4441/LTC4441-1 is an N-channel MOSFET gate driver that can supply up to 6A of peak output current. The chip is designed to operate with a supply voltage of up to 25V and has an adjustable linear regulator for the gate drive. The gate drive voltage can be programmed between 5V and 8V.The LTC4441/LTC4441-1 features a logic threshold driver input. This input can be driven below ground or above the driver supply. A dual function control input is provided to disable the driver or to force the chip into shutdown mode with <12µA of supply current. Undervoltage lockout and overtemperature protection circuits will disable the driver output when activated. The LTC4441 also comes with an open-drain output that provides adjustable leading edge blanking to prevent ringing when sensing the source current of the power MOSFETs.The LTC4441 is available in a thermally enhanced 10-lead MSOP package. The LTC4441-1 is the SO-8 version without the blanking function.Protected by U.S. Patents including 6677210.ApplicationsPower SuppliesMotor/Relay ControlLine DriversCharge Pumps

The LTC4442 is a high frequency gate driver designed to drive two N-channel MOSFETs in a synchronous buck DC/DC converter topology. The powerful driver capability reduces switching losses in MOSFETs with high gate capacitance.The LTC4442 features a separate supply for the input logic to match the signal swing of the controller IC. If the input signal is not being driven, the LTC4442 activates a shutdown mode that turns off both external MOSFETs. The input logic signal is internally level-shifted to the bootstrapped supply, which may function at up to 42V above ground.The LTC4442 contains undervoltage lockout circuits on both the driver and logic supplies that turn off the external MOSFETs when an undervoltage condition is present. The LTC4442 and LTC4442-1 have different undervoltage lockout thresholds to accommodate a wide variety of applications. An adaptive shoot-through protection feature is also built-in to prevent power loss resulting from MOSFET cross-conduction current.The LTC4442/LTC4442-1 are available in the thermally enhanced 8-lead MSOP package.ApplicationsDistributed Power ArchitecturesHigh Density Power Modules

The LTC4444-5 is a high frequency high voltage gate driver that drives two N-channel MOSFETs in a synchronous DC/DC converter with supply voltages up to 100V. This powerful driver reduces switching losses in MOSFETs with high gate capacitance.The LTC4444-5 is configured for two supply-independent inputs. The high side input logic signal is internally level-shifted to the bootstrapped supply, which may function at up to 114V above ground.The LTC4444-5 contains undervoltage lockout circuits that disable the external MOSFETs when activated. Adaptive shoot-through protection prevents both MOSFETs from conducting simultaneously.ApplicationsDistributed Power ArchitecturesAutomotive Power SuppliesHigh Density Power ModulesTelecommunication Systems