Analog Devices

The LTC3375 is a digitally programmable high efficiency multioutput power supply IC. The DC/DCs consist of eight synchronous buck converters (IOUTup to 1A each) all powered from independent 2.25V to 5.5V input supplies.DC/DC enables, output voltages, operating modes, and phasing may all be independently programmed over I2C or used in standalone mode via simple I/O with power-up defaults. The DC/DCs may be used independently or in parallel to achieve higher output currents of up to 4A per output with a shared inductor. Alarm levels for high die temperature may also be programmed via I2C with a maskable IRQ output for monitoring DC/DC and system faults.Pushbutton ON/OFF/RESET control, power-on reset, and a watchdog timer provide flexible and reliable power-up sequencing and system monitoring. The LTC3375 is available in a low profile 48-lead 7mm × 7mm QFN package.ApplicationsGeneral Purpose Multichannel Power SuppliesIndustrial/Automotive/Communications

The LTC3376 is a highly flexible multioutput power supply IC. The device includes four synchronous buck converters, configured to share eight 1.5A power stages, powered from independent 3V to 20V inputs. The DC/DCs are assigned to one of fifteen power configurations via pin strappable CFG0 to CFG3 pins. The LTC3376 includes the integration of ceramic capacitors into the package for the BST pins thereby saving PCB space. The common buck switching frequency may be programmed with an external resistor, synchronized to an external oscillator, or set to a default internal 2MHz clock.The operating mode for all DC/DCs may be programmed via the SYNC/MODE pin for Burst Mode or forced continuous mode operation. The PGOOD1 to PGOOD4 outputs indicate when each enabled DC/DC is within a specified percentage of its final output.Current monitors allow for external monitoring of each buck’s load. The EXTVCCpin allows for the internal circuitry to run from a 3V to 5.5V rail for improved efficiency.Precision RUN pin thresholds facilitate power-up sequencing. The LTC3376 is available in a 64 lead 7mm × 7mm BGA (0.8mm ball pitch).ApplicationsTelecom/Industrial12V Distributed Power Systems

The LTC3388-1/LTC3388-3 are high efficiency step-down DC/DC converters with internal high side and synchronous power switches that draw only 720nA typical DC supply current at no load while maintaining output voltage regulation.Capable of supplying 50mA of load current, the LTC3388-1/LTC3388-3 also incorporate an accurate undervoltage lockout (UVLO) feature to disable the converter and maintain a low quiescent current state when the input voltage falls below 2.3V. In regulation, the LTC3388-1/LTC3388-3 enter a sleep state in which both input and output quiescent currents are minimal. The buck converter turns on and off as needed to maintain regulation. An additional standby mode disables buck switching while the output is in regulation for short duration loads requiring low ripple.Output voltages of 1.2V, 1.5V, 1.8V, 2.5V (LTC3388-1) and 2.8V, 3.0V, 3.3V, 5.0V (LTC3388-3) are pin selectable. The LTC3388-1/LTC3388-3 can operate with VINup to 20V while the no load quiescent current remains below 1μA.ApplicationsKeep Alive Power for Portable ProductsIndustrial Control SuppliesDistributed Power SystemsBattery-Operated Devices

The LTC3400-1 is a synchronous, fixed frequency, stepup DC/DC converter delivering high efficiency in a 6-lead ThinSOT™package. Capable of supplying 3.3V at 100mA from a single AA cell input, the device contains an internal NMOS switch and PMOS synchronous rectifier.A switching frequency of 1.2MHz 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 LTC3400-1 features automatic shifting to power saving Burst Mode operation at light loads. In shutdown, VOUTand VINare connected, which allows the input battery to be used for backup power. The LTC3400-1 features low shutdown current of under 1µA.The LTC3400-1 is offered in the low profile (1mm)SOT-23 package.US Patent Numbers 5,481,178; 6,580,258; 6,304,066; 6,127,815; 6,498,466; 6,611,131.FeaturesLTC3400Burst ModeLTC3400BBurst Mode DisabledLTC3400-1Connects Vin to Vout In ShutdownApplicationsPagersMP3 PlayersDigital CamerasLCD Bias SuppliesHandheld InstrumentsWireless HandsetsGPS Receivers

The LTC3401 is a high efficiency, fixed frequency, step-up DC/DC converter that operates from an input voltage below 1V. The device includes a 0.16Ω N-channel MOSFET switch and a 0.18Ω P-channel synchronous rectifier. Switching frequencies up to 3MHz are programmed with an external timing resistor and the oscillator can be synchronized to an external clock. An external Schottky diode is optional but will slightly improve efficiency.Quiescent current is only 38µA in Burst Mode operation, maximizing battery life in portable applications. Burst Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/SYNC pin has either a clock or is driven low, then fixed frequency switching is enabled.Other features include 1µA shutdown, antiringing control, open-drain power good output, thermal shutdown and current limit. The LTC3401 is available in the 10-lead thermally enhanced MSOP package. Higher current applications should use the 2A rated LTC3402 synchronous boost converter. Applications that require VOUT< 2.6V should use the LTC3423.ApplicationsPagersHandheld InstrumentsCordless PhonesWireless HandsetsGPS ReceiversBattery BackupCCFL Backlights

The LTC3402 is a high efficiency, fixed frequency, step-up DC/DC converter that operates from an input voltage below 1V. The device includes a 0.16Ω N-channel MOSFET switch and a 0.18Ω P-channel synchronous rectifier. Switching frequencies up to 3MHz are programmed with an external timing resistor and the oscillator can be synchronized to an external clock. An external Schottky diode is optional but will slightly improve efficiency.Quiescent current is only 38µA in Burst Mode operation, maximizing battery life in portable applications. Burst Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/SYNC pin has either a clock or is driven low, then fixed frequency switching is enabled.Other features include a 1µA shutdown, antiringing control, open-drain power good output, thermal shutdown and current limit. The LTC3402 is available in the 10-lead thermally enhanced MSOP package. Lower current applications should use the 1A rated LTC3401 synchronous boost converter. Applications that require VOUT< 2.6V should use the LTC3424.ApplicationsCellular TelephonesHandheld ComputersMP3 Players2-Way PagersGPS ReceiversBattery Backup SuppliesCCFL Backlights

The LTC3405A is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. Supply current during operation is only 20µA and drops to <1µA in shutdown. The 2.5V to5.5V input voltage range makes the LTC3405A ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors.The LTC3405A is specifically designed to work well with ceramic output capacitors, achieving very low output voltage ripple and a small PCB footprint.The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.8V feedback reference voltage. The LTC3405A is available in a low profile (1mm) ThinSOT package.For fixed 1.5V and 1.8V output versions, refer to theLTC3405A-1.5/LTC3405A-1.8 data sheet.Protected by U.S. Patents, including 6580258, 5481178.VoutFeaturesLTC3405Adj.-LTC3405AAdj.Stable With All Ceramic CapsLTC3405A-1.3751.375VStable With All Ceramic CapsLTC3405A-1.51.5VStable With All Ceramic CapsLTC3405A-1.81.8VStable With All Ceramic CapsApplicationsCellular TelephonesPersonal Information AppliancesWireless and DSL ModemsDigital Still CamerasMP3 PlayersPortable Instruments

The LTC3406B is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.5V and 1.8V. Supply current with no load is 300µA and drops to <1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3406B ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. PWM pulse skipping mode operation provides very low output ripple voltage for noise sensitive applications.Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The LTC3406B is available in a low profile (1mm) ThinSOT package. Refer to LTC3406 for applications that require Burst Mode®operation.VOUTFSWFeaturesLTC3406Adj.1.5MHzBurst ModeLTC3406-1.21.2V1.5MHzBurst ModeLTC3406-1.51.5V1.5MHzBurst ModeLTC3406-1.81.8V1.5MHzBurst ModeLTC3406BAdj1.5MHzBurst Mode DisabledLTC3406B-1.21.2V1.5MHzBurst Mode DisabledLTC3406B-2Adj.2.25MHzBurst Mode DisabledLTC3406AAdj.1.5MHzLow Ripple Burst ModeLTC3406ABAdj.1.5MHzBurst Mode DisabledLTC3406AB-2Adj.2.25MHzBurst Mode DisabledApplicationsCellular TelephonesPersonal Information AppliancesWireless and DSL ModemsDigital Still CamerasMP3 PlayersPortable Instruments

The LTC3407-4 is a dual, constant frequency, synchronous step down DC/DC converter. Intended for low power applications, it operates from 2.5V to 5.5V input voltage range and has a constant 2.25MHz switching frequency, allowing the use of tiny, low cost capacitors and inductors with a profile ≤1mm. Each output voltage is adjustable from 0.6V to 5V. Internal synchronous 0.35Ω, 1.2A power switches provide high efficiency without the need for external Schottky diodes.A user selectable mode input is provided to allow the user to trade-off noise ripple for low power efficiency. Burst Mode®operation provides high efficiency at light loads, while Pulse Skip Mode provides low noise ripple at light loads.To further maximize battery life, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only 40µA. In shutdown, the device draws <1µA.The LTC3407-4 is identical to the LTC3407-2 except for the reduced power-on reset delay time.IoutFswFeaturesLTC34072x 600mA1.5MHzLTC3407-22x 800mA2.25MHzLTC3407-32x 800mA2.25MHzFixed 1.8V/3.3VLTC3407-42x 800mA2.25MHzReduced POR DelayLTC3407A2x 600mA1.5MHzLow Ripple Burst ModeLTC3407A-22x 800mA2.25MHzLow Ripple Burst ModeApplicationsPDAs/Palmtop PCsDigital CamerasCellular PhonesPortable Media PlayersPC CardsWireless and DSL Modems