Analog Devices

The LTC3526/LTC3526B are synchronous, fixed frequency step-up DC/DC converters with output disconnect. Synchronous rectification enables high efficiency in the low profile 2mm × 2mm DFN package. Battery life in single AA/AAA powered products is extended further with an 850mV start-up voltage and operation down to 500mV once started.A switching frequency of 1MHz minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. The current mode PWM design is internally compensated, reducing external parts count. The LTC3526 features automatic Burst Mode operation at light load conditions, while the LTC3526B features continuous switching at light loads. Anti-ringing control circuitry also reduces EMI concerns by damping the inductor in discontinuous mode. Additional features include a low shutdown current of under 1μA and thermal shutdown.The LTC3526/LTC3526B are housed in a 2mm × 2mm × 0.75mm DFN package.For new designs, we recommend the LTC3526L/LTC3526LB.Startup VoltageFrequencyBurst ModeNotesLTC35261V1MHzYesNot Recommended For New DesignsLTC3526B1V1MHzNoNot Recommended For New DesignsLTC3526-21V2MHzYesNot Recommended For New DesignsLTC3526B-21V2MHzNoNot Recommended For New DesignsLTC3526L0.85V1MHzYesLTC3526LB0.85V1MHzNoLTC3526L-20.85V2MHzYesLTC3526LB-20.85V2MHzNoAPPLICATIONSMedical InstrumentsFlash-Based MP3 PlayersNoise Canceling HeadphonesWireless MiceBluetooth Headsets

The LTC3527/LTC3527-1 are dual high efficiency, step-up DC/DC converters in a space saving 16-lead 3mm × 3mm QFN package. Battery life is maximized with a 700mV startup voltage and operation down to 500mV once started. TheSHDNand PGOOD pins enable the converters to be sequenced or started together.The LTC3527/LTC3527-1 limit inrush current during startup. Selectable 1.2MHz or 2.2MHz operation provides a choice between the highest efficiency or smallest solution footprint. The current mode PWM design is internally compensated reducing external parts count. Burst Mode operation or fixed frequency operation is selectable via the MODE pin. Anti-ring circuitry reduces EMI in discontinuous mode. This device also features thermal shutdown.True output disconnect allows the output to be completely open in shutdown. The LTC3527-1 actively discharges VOUT1or VOUT2when its respectiveSHDNgoes low. Quiescent current in shutdown is less than 2μA.ApplicationsMP3/Personal Media PlayersNoise Canceling/Bluetooth HeadsetsWireless MicePortable Medical Instruments

The LTC3528/LTC3528B are synchronous, fixed frequency step-up DC/DC converters with output disconnect. High efficiency synchronous rectification, in addition to a 700mV start-up voltage and operation down to 500mV once started, provides longer run-time for single or multiple cell battery-powered products.A switching frequency of 1MHz minimizes solution foot- print by allowing the use of tiny, low prole inductors and ceramic capacitors. The current mode PWM is internally compensated, simplifying the design process. The LTC3528 enters Burst Mode operation at light loads, while the LTC3528B features continuous switching at light loads. Anti-ringing circuitry reduces EMI by damping the inductor in discontinuous mode. Additional features include a low shutdown current, open-drain power good output, short- circuit protection and thermal overload protection.The LTC3528/LTC3528B are offered in an 8-lead 3mm x 2mm x 0.75mm DFN package.FrequencyBurst ModeLTC35281MHzYesLTC3528B1MHzNoLTC3528-22MHzYesLTC3528B-22MHzNoApplicationsMedical InstrumentsFlash-Based MP3 PlayersNoise Canceling HeadphonesWireless MiceBluetooth Headsets

The LTC3529 is a 5V output, synchronous, fixed frequency step-up DC/DC converter optimized for USB On-The-Go (OTG) hosting applications. This compact USB OTG 5V VBUSconverter features a 1.5MHz switching frequency, internal compensation and a tiny 2mm × 3mm DFN package. The LTC3529 can operate from input voltages as low as 1.8V.USB OTG-specific features include a fault fl ag with 22ms deglitching to indicate when the bus is overloaded, output disconnect and short circuit protection. Following a fault, the LTC3529 can be programmed to either latch-off or restart after a time-out duration.Additional features include a <1μA shutdown mode, soft-start, inrush current limiting and thermal overload protection. Anti-ring circuitry reduces EMI during low power operation. The LTC3529 is offered in an 8-Lead 2mm × 3mm × 0.75mm DFN package.ApplicationsPersonal Media PlayersDigital Video CamerasDigital Multimedia Broadcast TunersDigital CamerasSmart Phones

The LTC3530 is a wide VINrange, highly efficient, fixed frequency, buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for single lithium-ion, two-cell alkaline or NiMH applications where the output voltage is within the battery voltage range.The LTC3530 is pin compatible with the LTC3440 buckboost DC/DC converter but adds programmable automatic Burst Mode operation and extends the VIN/VOUTrange to 1.8V. Switching frequencies up to 2MHz are programmed with an external resistor. Automatic Burst Mode operation allows the user to program the load current threshold for Burst Mode operation using a single resistor from the BURST pin to GND.Other features include 1µA shutdown, short circuit protection, programmable soft-start control, current limit and thermal shutdown. The LTC3530 is available in a thermally enhanced 10-lead (3mm × 3mm) DFN or MSOP package.ApplicationsMP3 PlayersHandheld InstrumentsDigital CamerasSmart PhonesPortable GPS UnitsMiniature Hard Disk Drive Power

The LTC3531/LTC3531-3.3/LTC3531-3 are synchronous buck-boost DC/DC converters that operate from input voltages above, below or equal to the output voltage. The topology incorporated in the ICs provides a continuous transfer through all operating modes, making the product ideal for single cell Li-Ion and multicell alkaline or nickel applications. The converters operate in Burst Mode, minimizing solution footprint and component count as well as providing high conversion efficiency over a wide range of load currents.The devices include two 0.5Ω N-channel MOSFET switches and two P-channel switches (0.5Ω, 0.8Ω). Quiescent current is typically 16μA, making the parts ideal for battery power applications. Other features include a <1μA shutdown current, current limiting, thermal shutdown and output disconnect. The parts are offered in a 6-pin ThinSOT™package for fixed voltage versions or a 3mm × 3mm DFN package for fixed and adjustable versions.ApplicationsHandheld InstrumentsMP3 PlayersHandheld computersPDA/GPS

The LTC3532 is a high efficiency, fixed frequency, buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for single lithium-ion, multicell alkaline or NiMH applications where the output voltage is within the battery voltage range.The device includes two 0.36Ω N-channel MOSFET switches and two 0.42Ω P-channel switches. Switching frequencies up to 2MHz are programmed with an external resistor. Quiescent current is only 35μA in Burst Mode operation, maximizing battery life in portable applications. Automatic Burst Mode operation allows the user to program the load current for Burst Mode operation or to control it manually.Other features include a 1μA shutdown, soft-start control, thermal shutdown, and peak current limit. The LTC3532 is available in a low profile (0.75mm) 10-lead (3mm × 3mm) DFN and 10-lead MSOP packages.ApplicationsMiniature Hard Disk Drive Power SupplyMP3 PlayersHandheld InstrumentsDigital CamerasHandheld Terminals

The LTC3534 is a wide VINrange, highly efficient, fixed frequency, buck-boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for multi-cell Alkaline/NiMH or single Lithium-Ion/Polymer applications where the output voltage is within the battery voltage range.The LTC3534 offers extended VINand VOUTranges of 2.4V to 7V and 1.8V to 7V, respectively. Quiescent current is only 25μA in Burst Mode operation, maximizing battery life in portable applications. Burst Mode operation is user controlled and can be enabled by driving the PWM pin low. If the PWM pin is driven high then fixed frequency switching is enabled.Other features include fixed 1MHz operating frequency, a <1μA shutdown, short-circuit protection, programmable soft-start, current limit and thermal overload protection. The LTC3534 is available in the thermally enhanced 16-lead (3mm × 5mm) DFN and 16-lead GN packages.ApplicationsMedical InstrumentsPortable Barcode ReadersPortable Inventory TerminalsUSB to 5V SupplyHandheld GPS

The LTC3535 is a dual channel, synchronous, fixed frequency step-up DC/DC converter with output disconnect. Extended battery life in single AA/AAA powered products is realized with a 680mV start-up voltage and operation down to 500mV once started.A switching frequency of 1MHz minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. The current mode PWM design is internally compensated, reducing external parts count. The LTC3535 features Burst Mode operation at light load conditions allowing it to maintain high efficiency over a wide range of load. Anti-ring circuitry reduces EMI by damping the inductor in discontinuous mode. Additional features include a low shutdown current of under 1μA and thermal shutdown.The LTC3535 is housed in a 3mm × 3mm × 0.75mm DFN package.ApplicationsMedical InstrumentsNoise Canceling HeadphonesEnergy HarvestingBluetooth Headsets

The LTC3536 is an extended VINrange, fixed frequency, synchronous buck-boost DC/DC converter that operates from input voltages above, below or equal to the regulated output voltage. The topology incorporated in the LTC3536 provides low noise operation, making it ideal for RF and precision measurement applications.The device can produce up to 1A of continuous output current, and it includes two N-channel and two P-channel MOSFET switches. Switching frequencies up to 2MHz can be programmed with an external resistor and the oscillator can be synchronized to an external clock. Quiescent current is only 32μA in Burst Mode operation, maximizing battery life in portable applications. Burst Mode operation is user controlled and improves efficiency at light loads.Other features include a 1μA shutdown current, internal soft-start, overtemperature protection and current limit. The LTC3536 is available in 12-pin thermally enhanced MSOP and 10-pin (3mm × 3mm) DFN packages.ApplicationsWireless Inventory TerminalsHandheld Medical InstrumentsWireless Locators, MicrophonesSupercapacitor Backup Power Supply