Analog Devices Inc./Maxim Integrated

The LTC3861-1 is a dual PolyPhase®synchronous stepdown switching regulator controller for high current distributed power systems, digital signal processors, and other telecom and industrial DC/DC power supplies. It uses a constant-frequency voltage mode architecture combined with very low offset, high bandwidth error amplifiers and a remote output sense differential amplifier for excellent transient response and output regulation.The controller incorporates lossless inductor DCR current sensing to maintain current balance between phases and to provide overcurrent protection. The chip operates from a VCCsupply between 3V and 5.5V and is designed for stepdown conversion from VINbetween 3V and 24V to output voltages between 0.6V and VCC– 0.5V.Inductor current reversal is disabled during soft-start to safely power prebiased loads. The constant operating frequency can be synchronized to an external clock or linearly programmed from 250kHz to 2.25MHz. Up to six LTC3861-1 controllers can operate in parallel for 1-, 2-, 3-, 4-, 6- or 12-phase operation.The LTC3861-1 is pin-to-pin compatible with the LTC3860. It is available in a 32-pin 5mm × 5mm QFN package. The LTC3861is a 36-pin QFN version of the LTC3861-1, which has dual differential output voltage sense amplifiers.# Diff AmpsConfig PinPackageLTC38612Yes5 x 6 QFN-36LTC3861-11No5 x 5 QFN-32ApplicationsHigh Current Distributed Power SystemsDSP, FPGA and ASIC SuppliesDatacom and Telecom SystemsIndustrial Power Supplies

The LTC3862 is a two phase constant frequency, current mode boost and SEPIC controller that drives N-channel power MOSFETs. Two phase operation reduces system filtering capacitance and inductance requirements.The operating frequency can be set with an external resistor over a 75kHz to 500kHz range and can be synchronized to an external clock using the internal PLL. Multi-phase operation is possible using the SYNC input, the CLKOUT output and the PHASEMODE control pin allowing 2-, 3-, 4-, 6- or 12-phase operation.Other features include an internal 5V LDO with undervoltage lockout protection for the gate drivers, a precision RUN pin threshold with programmable hysteresis, soft-start and programmable leading edge blanking and maximum duty cycle.Part NumberVin RangeINTVccVINONVINOFFLTC38624V to 36V5V3.3V2.9VLTC3862-18.5V to 36V10V7.5V7.0VLTC3862-25.5V to 36V10V4.4V3.9VAPPLICATIONSAutomotive, Telecom and Industrial Power Supplies

The LTC3865/LTC3865-1 are high performance dual synchronous step-down DC/DC switching regulator controllers that drive all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows a phase-lockable frequency of up to 770kHz. Power loss and noise are minimized by operating the two 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. Independent track/soft-start pins for each controller ramp the output voltage during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The MODE/PLLIN pin selects among Burst Mode®operation, pulse-skipping mode, and continuous inductor current mode. The output voltages can be precisely programmed by pin strapping or external resistors.The LTC3865/LTC3865-1 are available in low profile (5mm × 5mm) 32-pin QFN and 38-Lead thermally enhanced TSSOP packages.ApplicationsDC Power Distribution Systems