Analog Devices Inc./Maxim Integrated

The LTC3649 is a high efficiency 60V, 4A synchronous monolithic step-down regulator. The regulator features a single resistor programmable output voltage, internal compensation and high efficiencies over a wide VOUTrange.The step-down regulator operates from an input voltage range of 3.1V to 60V and provides an adjustable rail-to-rail output range from (VIN– 0.5V) to ground while delivering up to 4A of output current. The switching frequency is also adjusted with an external resistor. A user-selectable mode input is provided to allow the user to trade off ripple noise for efficiency at light loads; Burst Mode operation provides the highest efficiency at light loads, while forced continuous mode provides low output ripple. The MODE/SYNC pin can also be used to allow the user to synchronize the switching frequency to an external clock.The LTC3649 operates with a peak current mode architecture that allows for fast transient response with inherent cycle-to-cycle current limit protection. It also features programmable output current limit, current monitoring and input voltage regulation.ApplicationsIndustrial ApplicationsAutomotive Applications

The LTC3672B-1 is a triple power supply composed of a 400mA synchronous buck regulator and two 150mA low dropout linear regulators (LDOs), where one of the LDOs can be powered from the buck output to improve efficiency. Constant-frequency 2.25MHz operation is maintained down to very light loads. The input supply range of 2.9V to 5.5V is especially well-suited for single-cell Lithium-Ion and Lithium-Polymer applications, and for powering low voltage ASICs from 3.3V or 5V rails.The LTC3672B-1 regulates 1.8V at the buck output, 1.2V at the LDO1 output, and 2.8V at the LDO2 output. External component count is minimal—all that is needed is a single inductor, an input capacitor, and output capacitors for each of the three outputs. Control loop compensation is internal to the LTC3672B-1.The LTC3672B-1 is available in a 2mm x 2mm x 0.75mm 8-Lead DFN package.Buck VoutLDO 1LDO 2LTC3672B-11.8V1.2V2.8VLTC3672B-21.2V2.8V1.8VApplicationsDMB CellphonesHandheld Products (PDA, PMP, GPS)Multivoltage Power for Digital Logic, I/O, FPGAs, CPLDs, ASICs, CPUs, and RF Chipsets

The LTC3675/LTC3675-1 are a digitally programmable high efficiency multioutput power supplies plus dual string LED driver ICs optimized for high power single cell Li-Ion/Polymer applications. The DC/DCs consist of four synchronous buck converters (1A/1A/500mA/500mA), one synchronous boost DC/DC (1A), and one buck-boost DC/DC (1A) all powered from a 2.7V to 5.5V input. The 40V LED driver can regulate up to 25mA of current through two LED strings with up to 10 LEDs each. The LED driver may also be configured as a general purpose high voltage boost converter.DC/DC enables, output voltages, switch slew rates and operating modes may all be independently programmed over I2C or used in standalone mode via simple I/O and power-up defaults. The buck DC/DCs may be used independently or paralleled to achieve higher output currents with a shared inductor. LED enable, 60dB brightness control and up/down gradation are programmed using I2C. Alarm levels for low VINand high die temperature may also be programmed via I2C with a maskable interrupt output to monitor DC/DC and system faults.Pushbutton ON/OFF/RESET control and a power-on reset output provide flexible and reliable power-up sequencing. The LTC3675/LTC3675-1 are available in a low profile (0.75mm), thermally enhanced 44-lead 4mm × 7mm QFN package.ApplicationsHigh Power (5W to 10W) Single Cell Li-Ion/Polymer ApplicationsPortable Industrial Applications, Handy Terminals, Portable InstrumentsMultioutput Low Voltage Power Supplies

The LTC3675/LTC3675-1 are a digitally programmable high efficiency multioutput power supplies plus dual string LED driver ICs optimized for high power single cell Li-Ion/Polymer applications. The DC/DCs consist of four synchronous buck converters (1A/1A/500mA/500mA), one synchronous boost DC/DC (1A), and one buck-boost DC/DC (1A) all powered from a 2.7V to 5.5V input. The 40V LED driver can regulate up to 25mA of current through two LED strings with up to 10 LEDs each. The LED driver may also be configured as a general purpose high voltage boost converter.DC/DC enables, output voltages, switch slew rates and operating modes may all be independently programmed over I2C or used in standalone mode via simple I/O and power-up defaults. The buck DC/DCs may be used independently or paralleled to achieve higher output currents with a shared inductor. LED enable, 60dB brightness control and up/down gradation are programmed using I2C. Alarm levels for low VINand high die temperature may also be programmed via I2C with a maskable interrupt output to monitor DC/DC and system faults.Pushbutton ON/OFF/RESET control and a power-on reset output provide flexible and reliable power-up sequencing. The LTC3675/LTC3675-1 are available in a low profile (0.75mm), thermally enhanced 44-lead 4mm × 7mm QFN package.ApplicationsHigh Power (5W to 10W) Single Cell Li-Ion/Polymer ApplicationsPortable Industrial Applications, Handy Terminals, Portable InstrumentsMultioutput Low Voltage Power Supplies

The LTC3701 is a 2-phase dual constant frequency current mode step-down DC/DC controller providing excellent load and line regulation. Power loss and noise due to ESR of the input capacitor are minimized by operating the two controller output stages out-of-phase.The LTC3701 provides a 0.8V ±2% voltage reference and consumes only 460µA of quiescent current. To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle).Switching frequency is internally set at 550kHz, allowing the use of small inductors and capacitors. For noise sensitive applications, the LTC3701 can be externally synchronized using its phase-locked loop. The frequency can also be externally set from 300kHz to 750kHz by applying a voltage to the PLLLPF pin. Burst Mode operation is inhibited during synchronization or when the EXTCLK/MODE pin is pulled low to reduce noise and RF interference.The LTC3701 contains independent internal soft-start circuitry for each controller. Other features include a power good output voltage monitor and output overvoltage and short-circuit protection.The LTC3701 is available in a small footprint 16-lead narrow SSOP package.ApplicationsOne or Two Lithium-Ion Powered ApplicationsNotebook and Handheld ComputersPersonal Digital AssistantsPortable InstrumentsDistributed DC Power Systems