Analog Devices Inc./Maxim Integrated

The LTC1624 is a current mode switching regulator controller that drives an external N-channel power MOSFET using a fixed frequency architecture. It can be operated in all standard switching configurations including boost, step-down, inverting and SEPIC. Burst Mode™operation provides high efficiency at low load currents. A maximum high duty cycle limit of 95% provides low dropout operation which extends operating time in battery-operated systems.The operating frequency is internally set to 200kHz, allowing small inductor values and minimizing PC board space. The operating current level is user-programmable via an external current sense resistor. Wide input supply range allows operation from 3.5V to 36V (absolute maximum).A multifunction pin (ITH/RUN) allows external compensation for optimum load step response plus shutdown. Soft start can also be implemented with the ITH/RUN pin to properly sequence supplies.ApplicationsNotebook and Palmtop Computers, PDAsCellular Telephones and Wireless ModemsBattery-Operated Digital DevicesDC Power Distribution SystemsBattery Chargers

The LTC1628/LTC1628-PG are high performance dual step-down switching regulator controllers that drive all N-channel synchronous 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 capacitors 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. The precision 0.8V reference and power good output indicator are compatible with future microprocessor generations, and a wide 3.5V to 30V (36V maximum) input supply range encompasses all battery chemistries.A RUN/SS pin for each controller provides both soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when overcurrent latchoff is disabled. Output overvoltage protection circuitry latches on the bottom MOSFET until VOUTreturns to normal. The FCB mode pin can select among Burst Mode, constant frequency mode and continuous inductor current mode or regulate a secondary winding. The LTC1628-PG includes a power good output pin that replaces the FLTCPL, fault coupling control pin of the LTC1628.ApplicationsNotebook and Palmtop Computers, PDAsBattery ChargersPortable InstrumentsBattery-Operated Digital DevicesDC Power Distribution Systems

The LTC1628-SYNC is a high performance dual step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows phase-lockable frequency of up to 300kHz. Power loss and noise due to the ESR of the input capacitors 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. The precision 0.8V reference and power good output indicator are compatible with future microprocessor generations, and a wide 3.5V to 30V (36V maximum) input supply range encompasses all battery chemistries.A RUN/SS pin for each controller provides both soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when overcurrent latchoff is disabled. Output overvoltage protection circuitry latches on the bottom MOSFET until VOUTreturns to normal. The FCB mode pin can select among Burst Mode, constant frequency mode and continuous inductor current mode or regulate a secondary winding.ApplicationsNotebook and Palmtop Computers, PDAsTelecom SystemsBattery-Operated Digital DevicesDC Power Distribution Systems

The LTC1629/LTC1629-PG are multiple phase, dual, synchronous step-down current mode switching regulator controllers that drive N-channel external power MOSFET stages in a phase-lockable fixed frequency architecture. The PolyPhase™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 output clock signal allows expansion for up to 12 evenly phased controllers for systems requiring 15A to 200A of output current. The multiple phase technique effectively multiplies the fundamental frequency by the number of channels used, improving transient response while operating each channel at an optimum frequency for efficiency. Thermal design is also simplified.An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required for high current applications.A RUN/SS pin provides both soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when the overcurrent latch-off is disabled. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC1629-PG includes a power good output pin that replaces the AMPMD control pin of the LTC1629.ApplicationsDesktop ComputersInternet ServersLarge Memory ArraysDC Power Distribution Systems

The LTC1629-6 is a PolyPhase™synchronous stepdown current mode switching regulator controller with 0.6V reference that drives N-channel external power MOSFET stages in a phase-lockable fixed frequency architecture. The PolyPhase 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 output clock signal allows expansion for up to 12 evenly phased controllers for systems requiring 15A to 200A of output current. The multiple phase technique effectively multiplies the fundamental frequency by the number of channels used, improving transient response while operating each channel at an optimum frequency for efficiency. Thermal design is also simplified.An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required for high current applications.A RUN/SS pin provides both 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 over a wide range of output capacitance and ESR values. The LTC1629-6 includes a power good output pin that indicates when the output voltage is inside the ±10% tolerance window.ApplicationsDesktop ComputersInternet ServersLarge Memory ArraysDC Power Distribution Systems

The LTC1642 is a 16-pin Hot Swap™controller that allows a board to be safely inserted and removed from a live backplane. Using an external N-Channel pass transistor, the board supply voltage can be ramped up at an adjustable rate. A high side switch driver controls the N-Channel gate for supply voltages above 2.97V.The SENSE pin allows foldback limiting of the load current, with circuit breaker action after an adjustable delay time. The delay allows the part to power-up in current limit. The CRWBR output can be used to trigger an SCR for crowbar protection of the load if the input supply exceeds an adjustable threshold. TheRESEToutput can generate a system reset with adjustable delay when the supply voltage falls below an adjustable threshold. The ON pin cycles the board power. The LTC1642 is available in the 16-pin SSOP package.NotesLTC1642LTC1642ARecommended for applications where VCC is higher than 12VApplicationsHot Board InsertionElectronic Circuit BreakerInfiniBand™Systems

The LTC1642A is a 16-pin Hot Swap™ controller that allows a board to be safely inserted and removed from a live backplane. Using an external N-Channel pass transistor, the board supply voltage can be ramped up at an adjustable rate. A high side switch driver controls the N-Channel gate for supply voltages ranging from 2.97V to 16.5V.The SENSE pin allows foldback limiting of the load current, with circuit breaker action after an adjustable delay time. The delay allows the part to power-up in current limit. The CRWBR output can be used to trigger an SCR for crowbar protection of the load if the input supply exceeds an adjustable threshold. TheRESEToutput can generate a system reset with adjustable delay when the supply voltage falls below an adjustable threshold. The ON pin cycles the board power. The LTC1642A is available in the 16-pin SSOP package.NotesLTC1642LTC1642ARecommended for application where VCCis Higher than 12VApplicationsHot Board InsertionElectronic Circuit BreakerInfiniBand™Systems