Analog Devices

The LTC1703 is a dual switching regulator controller optimized for high efficiency with low input voltages. It includes two complete, on-chip, independent switching regulator controllers. Each is designed to drive a pair of external N-channel MOSFET devices in a voltage mode feedback, synchronous buck configuration. The LTC1703 includes digital output voltage adjustment on side 1 that conforms to the Intel Mobile VID specification. It uses a constant-frequency, true PWM design switching at 550kHz, minimizing external component size and cost and optimizing load transient performance. The synchronous buck architecture automatically shifts to discontinuous and then to Burst Mode®operation as the output load decreases, ensuring maximum efficiency over a wide range of load currents.The LTC1703 features an onboard reference trimmed to 1% and delivers better than 1.5% regulation at the converter outputs. An optional latching FAULT mode protects the load if the output rises 15% above the intended voltage. Each channel can be enabled independently; with both channels disabled, the LTC1703 shuts down and supply current drops below 100µA.ApplicationsMobile Pentium®III Processor SystemsMicroprocessor Core and I/O SuppliesMultiple Logic Supply GeneratorHigh Efficiency Power Conversion

The LTC1704/LTC1704B include a high power synchronous switching regulator controller plus a linear regulator controller. The switching regulator controller is designed to drive a pair of N-channel MOSFETs in a voltage mode, synchronous buck configuration to provide the main supply. The constant frequency, true PWM architecture switches at 550kHz, minimizing external component size, cost and optimizing load transient performance. The LTC1704 features automatic transition to power saving Burst Mode operation at light loads. The LTC1704B does not shift into Burst Mode operation at light loads, eliminating low frequency output ripple at the expense of light load efficiency. The linear regulator controller is designed to drive an external NPN power transistor to provide up to 2A of current to an auxiliary load.The LTC1704/LTC1704B deliver better than ±1.5% DC accuracy at the switcher outputs and ±2% at the linear regulator outputs. High performance feedback loops allow the circuit to keep total output regulation within ±5% under all transient conditions. An open-drain PGOOD output indicates when both outputs are within ±10% of their regulated values.ApplicationsMultiple Logic Supply GeneratorDistributed Power ApplicationsHigh Efficiency Power Conversion

The LTC1706-85 is a precision, digitally programmed resistive ladder which adjusts the output of any 0.8V-referenced regulator. Depending on the state of the five VID inputs, an output voltage between 1.05V and 1.825V is programmed in 25mV increments.The LTC1706-85 is designed specifically to program ADI's entire family of DC/DC converters in full compliance with the Intel Voltage Regulator Module (VRM) 8.5 specification.The LTC1706-85 programs the following ADI DC/DC converter products: LTC1622, LTC1628, LTC1629, LTC1702, LTC1735, LTC1735-1, LTC1772, LTC1773, LTC1778, LTC1929, LTC3728 and LTC3729.Consult factory for additional DC/DC converter products compatible with the LTC1706-85.ApplicationsServer/Desktop ComputersMultiprocessor Workstations and ServersMultiphase Processor Power Supply

The LTC1707 is a high efficiency monolithic current mode synchronous buck regulator using a fixed frequency architecture. The operating supply range is from 8.5V down to 2.85V, making it suitable for both single and dual lithium-ion battery-powered applications. Burst Mode operation provides high efficiency at low load currents. 100% duty cycle provides low dropout operation, extending operating time in battery-powered systems.The switching frequency is internally set at 350kHz, allowing the use of small surface mount inductors. For noise sensitive applications it can be externally synchronized up to 550kHz. Burst Mode operation is inhibited during synchronization or when the SYNC/MODE pin is pulled low preventing low frequency ripple from interfering with audio circuitry. Soft-start is provided by an external capacitor.The internal synchronous MOSFET switch increases efficiency and eliminates the need for an external Schottky diode, saving components and board space. Low output voltages down to 0.8V are easily achieved due to the 0.8V internal reference. The LTC1707 comes in an 8-lead SO package.ApplicationsCellular TelephonesPortable InstrumentsWireless ModemsRF CommunicationsDistributed Power SystemsSingle and Dual Cell Lithium

The LTC1708 is a dual adjustable 5-bit VID programmable step-down switching regulator controller that drives all N-Channel power MOSFET stages. A constant frequency current mode architecture allows adjustment of the frequency up to 300kHz. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two main controller output stages out of phase.OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The precision 0.8V reference is compatible with future microprocessor generations, and a wide 3.5V to 30V (36V maximum) input supply range that encompasses all battery chemistries. A power good output indicates when the output voltages are within 7.5% of their programmed value.A RUN/SS pin for each controller provides both soft-start and an optional timed, short-circuit shutdown. Other protection features include: internal foldback current limiting and an output overvoltage crowbar. The forced continuous control pin (FCB) can be used to inhibit BurstMode operation or to regulate a third, flyback output.ApplicationsNotebook and Palmtop Computers, PDAsPortable Instruments

The LTC1709-85 is a 2-phase, VID programmable, synchronous step-down switching regulator controller that drives two all N-channel external power MOSFET stages in a fixed frequency architecture. The 2-phase controller drives its two output stages out of phase at frequencies up to 300kHz to minimize the RMS ripple currents in both input and output capacitors. The 2-phase technique effectively multiplies the fundamental frequency by two, improving transient response while operating each channel at an optimum frequency for efficiency. Thermal design is also simplified.An operating mode select pin (FCB) can be used to select among three modes including Burst Mode®operation for highest efficiency. An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required in high current applications.The RUN/SS pin provides soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when the overcurrent latchoff is disabled. OPTI-LOOP compensation allows the transient response to be optimized for a wide range of output capacitors and ESR values.Vout RangeVRMLTC17091.3V to 3.5VVRM8.4LTC1709-70.925V to 2VMobileLTC1709-81.3V to 3.5VVRM8.4LTC1709-8.51.05V to 1.825VVRM8.5LTC1709-91.1V to 1.85VVRM9.0ApplicationsServer/Desktop ComputersInternet ServersLarge Memory ArraysDC Power Distribution Systems

The LTC1710 SMBus dual switch has two built-in 0.4Ω/300mA switches that are controlled by a 2-wire SMBus interface. With a low standby current of 14µA (3.3V), the LTC1710 operates over an input voltage range of 2.7V to 5.5V while maintaining the SMBus specified 0.6V VILand 1.4V VIHinput thresholds.Using the 2-wire interface, CLK and DATA, the LTC1710 follows SMBus’s Send Byte Protocol to independently control the two 0.4Ωinternal N-channel power switches, which are fully enhanced by on-board charge pumps.The LTC1710 has one three-state programmable address pin that allows three different addresses for a total of six available switches on the same bus. The LTC1710 also features a separate user-controlled drain supply (SW0D) to Switch 0 so that it can be used to control SMBus peripherals using a different power supply.ApplicationsHandheld Computer Power ManagementComputer Peripheral ControlLaptop Computer Power Plane SwitchingPortable Equipment Power ControlIndustrial Control SystemsACPI SMBus Interface

The LTC1726 is a triple supply monitor and microprocessor supervisory circuit with adjustable reset and watchdog functions intended for systems with multiple supply voltages. The part has a common open-drain reset output with an adjustable delay. The reset and watchdog time-out periods are both adjustable using external capacitors.Tight 1.5% accuracy specifications and glitch immunity ensure reliable reset operation without false triggering.TheRSToutput is guaranteed to be in the correct state for VCC5/VCC25or VCC3down to 1V. The LTC1726 may also be configured to monitor any one or two VCCinputs instead of three, depending on system requirements.The low (16μA typical) supply current makes the LTC1726 ideal for power-conscious systems.ApplicationsDesktop ComputersNotebook ComputersIntelligent InstrumentsPortable Battery-Powered EquipmentNetwork Servers

The LTC1727 is a triple supply monitor intended for systems with multiple supply voltages. Each supply monitor has its own open-drain output for individual supply monitoring. A common open-drain reset output remains low until all three supplies have been in compliance for 200ms. Tight 1.5% accuracy specifications and glitch immunity ensure reliable reset operation without false triggering.The LTC1728 is functionally identical to the LTC1727 without the individual monitor outputs.TheRSToutput is guaranteed to be in the correct state for VCC5/VCC25/VCC18or VCC3down to 1V. The LTC1727/LTC1728 may also be configured to monitor any one or two VCCinputs instead of three, depending on system requirements.Very low (10µA typical) supply current makes the LTC1727/LTC1728 ideal for power conscious systems.The LTC1727 is available in an 8-lead MSOP or SO package and the LTC1728 is available in a 5-lead SOT-23 package.ApplicationsDesktop ComputersNotebook ComputersIntelligent InstrumentsPortable Battery-Powered EquipmentNetwork Servers