Analog Devices Inc./Maxim Integrated

The LTC3736-2 is a 2-phase dual synchronous step-down switching regulator controller with tracking that drives external complementary power MOSFETs using few external components. The constant-frequency current mode architecture with MOSFET VDSsensing eliminates the need for sense resistors and improves efficiency. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out-of-phase.Pulse-skipping operation provides high efficiency at light loads. 100% duty cycle capability provides low dropout operation, extending operating time in battery-powered systems.The switching frequency can be programmed up to 750kHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications, the LTC3736-2 switching frequency can be externally synchronized from 250kHz to 850kHz. An internal soft-start, which can be lengthened externally, smoothly ramps the output voltage during start-up.The LTC3736-2 is available in the tiny thermally enhanced (4mm × 4mm) QFN and 24-lead narrow SSOP packages.Max Current Sense VoltageBurst ModeSoft StartSpread SpectrumLTC3736204mVYesNoNoLTC3736-1204mVNoNoYesLTC3736-2345mVNoYesNoApplicationsOne or Two Lithium-Ion Powered DevicesNotebook and Palmtop Computers, PDAsPortable InstrumentsDistributed DC Power Systems

The LTC3737 is a 2-phase dual step-down switching regulator controller that requires few external components. The constant frequency current mode architecture provides excellent AC and DC load and line regulation. MOSFET VDSsensing eliminates the need for current sense resistors and improves efficiency. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out of phase.Burst Mode operation provides high efficiency operation at light loads. 100% duty cycle provides low dropout operation and extends battery operating time.Switching frequency can be programmed up to 750kHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications, the LTC3737 can be externally synchronized from 250kHz to 850kHz.Other features include a power good output voltage monitor, a tracking input and internal soft-start.The LTC3737 is available in the low profile thermally enhanced (4mm × 4mm) QFN package or a 24-lead SSOP narrow package.Protected by U.S. Patents, including 5481178, 5731694, 5929620, 6144194, 6580258, 5994885ApplicationsOne or Two Lithium-Ion Powered DevicesNotebook and Palmtop Computers, PDAsPortable InstrumentsDistributed DC Power Systems

The LTC3770 is a synchronous step-down switching regulator controller with output voltage up/down tracking capability and voltage margining. Its advanced functions and high accuracy reference are ideal for powering high performance server, ASIC and computer memory systems.The LTC3770 uses a constant on-time, valley current mode control architecture to deliver very low duty factors without requiring a sense resistor. The operating frequency is selected by an external resistor and is compensated for variations in input supply voltage. An internal phase-lock loop allows the IC to be synchronized to an external clock.Fault protection is provided by an overvoltage comparator and input undervoltage lockout. The regulator current limit is user programmable. A wide supply range allows voltages as high as 32V to be stepped down to as low as a 0.6V output. Power supply sequencing is accomplished using an external soft-start timing capacitor.ApplicationsDistributed Power SystemsServer Power Supply

The LTC3772 is a constant frequency current mode step-down DC/DC controller in a low profile 8-lead SOT-23 (ThinSOT™) and a 3mm × 2mm DFN package. The No RSENSE™architecture eliminates the need for a current sense resistor, improving efficiency and saving board space.The LTC3772 automatically switches into Burst Mode operation at light loads to increase efficiency at low output current. It consumes only 40µA of quiescent current under a no-load condition.The LTC3772 incorporates an undervoltage lockout feature that shuts down the device when the input voltage falls below 2V. To maximize the runtime from a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550kHz allows the use of a small inductor and capacitors. An internal soft-start smoothly ramps the output voltage from zero to its regulation point.Burst ModeLTC3772YesLTC3772BNoApplications1- or 2-Cell Li-Ion Battery-Powered ApplicationsWireless DevicesPortable ComputersDistributed Power Systems

The LTC3772B is a constant frequency current mode step-down DC/DC controller in a low profile 8-lead SOT-23 (ThinSOT™) and a 3mm × 2mm DFN package. The No RSENSE™architecture eliminates the need for a current sense resistor, improving efficiency and saving board space.The LTC3772B automatically switches into pulse skipping operation at light loads. It consumes only 200μA of quiescent current under a no-load condition.The LTC3772B incorporates an undervoltage lockout feature that shuts down the device when the input voltage falls below 2V. To maximize the runtime from a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550kHz allows the use of a small inductor and capacitors. An internal soft-start smoothly ramps the output voltage from zero to its regulation point.Burst ModeLTC3772YesLTC3772BNoApplications1- or 2-Cell Li-Ion Battery-Powered ApplicationsWireless DevicesPortable ComputersDistributed Power Systems

The LTC3773 is a high performance, 3-phase, triple output synchronous step-down switching regulator controller with output voltage power up/down tracking capability. The controller allows for sequential, coincident or ratiometric tracking.This 3-phase controller drives its output stages with 120° phase separation at frequencies of up to 700kHz per phase minimizing the RMS input current. Light load efficiency can be maximized by using selectable Burst Mode operation. The 0.6V precision reference supports output voltages from 0.6V to 5V.Fault protection features include output overvoltage, input undervoltage lockout plus current foldback under short-circuit or overload conditions.ApplicationsServers, Telecom, Industrial Power SuppliesGeneral Purpose Multiple Rail DC/DCFPGA and DSP Requirements