The LTC3803 is a constant frequency current mode flyback controller optimized for driving N-channel MOSFETs in high input voltage applications. Constant frequency operation is maintained down to very light loads, resulting in less low frequency noise generation over a wide range of load currents. Slope compensation can be programmed with an external resistor.The LTC3803 provides ±1.5% output voltage accuracy and consumes only 240μA of quiescent current. Ground-referenced current sensing allows LTC3803-based converters to accept input supplies beyond the LTC3803’s absolute maximum VCC. A micropower hysteretic start-up feature allows efficient operation at high input voltages. For simplicity, the LTC3803 can also be powered from a high VIN through a resistor, due to its internal shunt regulator. An internal undervoltage lockout shuts down the LTC3803 when the input voltage is too low to provide sufficient gate drive to the external MOSFET.The LTC3803 is available in a low profile (1mm) 6-lead SOT-23 (ThinSOT™) package. Turn On Voltage Frequency LTC3803 8.7V 200kHz LTC3803-3 8.7V 300kHz LTC3803-5 4.8V 200kHz Applications Telecom Power Supplies 42V and 12V Automotive Power Supplies Auxiliary/Housekeeping Power Supplies Power Over Ethernet

The LTC3806 is a current mode synchronous flyback controller that drives N-channel power MOSFETs and requires very few external components. It is intended for medium power applications where multiple outputs are required. Synchronous rectification provides higher efficiency and improved output cross regulation than nonsynchronous converters.The IC contains all the necessary control circuitry including a 250kHz oscillator, precision undervoltage lockout circuit with hysteresis, gate drivers for primary and synchronous switches, current mode control circuitry and soft-start circuitry.Programmable soft-start reduces inrush currents. This makes it easier to design compliant Power Over Ethernet supplies.Low start-up current reduces power dissipation in the start-up resistor and reduces the size of the external startup capacitor.The LTC3806 is available in a 12-pin, exposed pad DFN package.Applications 48V Telecom Supplies 12V/42V Automotive 24V Industrial VoIP Phone Power Over Ethernet

The LTC3458L is a high efficiency, current mode, fixed frequency, step up DC/DC converter with true output disconnect and inrush current limiting. The LTC3458L is rated for up to 6V output and includes a 0.2Ω N-channel MOSFET switch and a 0.3Ω P-channel MOSFET synchronous rectifier. The LTC3458L is well suited for battery powered applications and includes programmable output voltage, switching frequency and loop compensation. The oscillator frequency can be set up to 1.5MHz or synchronized to an external clock.Quiescent current is only 12µA during Burst Mode operation maximizing battery life in portable applications. The Burst Mode current threshold, peak current limit, and softstart are externally programmable. Other features include <1µA shutdown current, antiringing control, and thermal limit. The LTC3458L is available in a low profile (0.75mm), 4mm × 3mm 12-pin DFN package.Protected by U.S. Patents including 5481178, 6304066, 6580258, 5511131, 6498466 Vout Range Switch Current LTC3458 2.0V to 7.5V 1.4A LTC3458L 2.0V to 6.0V 1.7A Applications Point-of-Load Regulators USB VBUS Power Portable GPS MP3 Players

The MAX1556/MAX1556A/MAX1557 are low-operating-current (16µA), fixed-frequency step-down regulators. High efficiency, low-quiescent operating current, low dropout, and minimal (27µA) quiescent current in dropout make these converters ideal for powering portable devices from 1-cell Li-ion or 3-cell alkaline/NiMH batteries. The MAX1556 delivers up to 1.2A; has pin-selectable 1.8V, 2.5V, and 3.3V outputs; and is also adjustable. The MAX1557 delivers up to 600mA; has pin-selectable 1V, 1.3V, and 1.5V outputs; and is also adjustable.The MAX1556/MAX1556A/MAX1557 contain a low-on-resistance internal MOSFET switch and synchronous rectifier to maximize efficiency and dropout performance while minimizing external component count. A proprietary topology offers the benefits of a high fixed-frequency operation while still providing excellent efficiency at both light and full loads. A 1MHz PWM switching frequency keeps components small. Both devices also feature an adjustable soft-start to minimize battery transient loading.The MAX1556/MAX1556A/MAX1557 are available in a tiny 10-pin TDFN (3mm x 3mm) package.ApplicationsCell Phones/SmartphonesDigital Cameras and CamcordersHandheld InstrumentsPDAs and Palmtop ComputersPortable MP3 and DVD Players

The MAX1589A low-dropout linear regulator operates from a +1.62V to +3.6V supply and delivers a guaranteed 500mA continuous load current with a low 175mV dropout. The high-accuracy (±0.5%) output voltage is preset to internally trimmed voltages from +0.75V to +3.0V. An active-low, open-drain reset output remains asserted for at least 70ms after the output voltage reaches regulation. This device is offered in 6-pin thin SOT23 and 6-pin, 3mm x 3mm thin DFN packages.An internal pMOS pass transistor maintains low supply current, independent of load and dropout voltage, making the MAX1589A ideal for portable battery-powered equipment such as personal digital assistants (PDAs), digital still cameras, cell phones, cordless phones, and notebook computers. Other features include logic-controlled shutdown, short-circuit protection, and thermal-overload protection.ApplicationsCD and MP3 PlayersCellular and PCS PhonesDigital Still CamerasHandheld ComputersNotebook ComputersPCMCIA CardsPersonal Digital Assistants (PDAs)

The MAX1630A–MAX1635A are buck-topology, stepdown, switch-mode, power-supply controllers that generate logic-supply voltages in battery-powered systems. These high-performance, dual-/triple-output devices include on-board power-up sequencing, power-good signaling with delay, digital soft-start, secondary winding control, low-dropout circuitry, internal frequency-compensation networks, and automatic bootstrapping.Up to 96% efficiency is achieved through synchronous rectification and Maxim's proprietary Idle Mode™ control scheme. Efficiency is greater than 80% over a 1000:1 load-current range, which extends battery life in system-suspend or standby mode. Excellent dynamic response corrects output load transients caused by the latest dynamic-clock CPUs within five 300kHz clock cycles. Strong 1A on-board gate drivers ensure fast external n-channel MOSFET switching.These devices feature a logic-controlled and synchronizable, fixed-frequency, pulse-width-modulation (PWM) operating mode. This reduces noise and RF interference in sensitive mobile communications and pen-entry applications. Asserting the Active-Low SKIP pin enables fixed-frequency mode for lowest noise under all load conditions.The MAX1630A–MAX1635A include two PWM regulators, adjustable from 2.5V to 5.5V with fixed 5.0V and 3.3V modes. All these devices include secondary feedback regulation, and the MAX1630A/MAX1632A/MAX1633A/MAX1635A each contain 12V/120mA linear regulators. The MAX1631A/MAX1634A include a secondary feedback input (SECFB), plus a control pin (STEER) that selects which PWM (3.3V or 5V) receives the secondary feedback signal. SECFB provides a method for adjusting the secondary winding voltage regulation point with an external resistor-divider, and is intended to aid in creating auxiliary voltages other than fixed 12V.The MAX1630A/MAX1631A/MAX1632A contain internal output overvoltage and undervoltage protection features. The MAX1630A family has improved RF immunity over the MAX1630 family.ApplicationsDesktop CPU Local DC-DC ConvertersNotebook and Subnotebook ComputersPDAs and Mobile Communicators

The MAX1963A/MAX1976A low-dropout linear regulators operate from a +1.62V to +3.6V supply and deliver a guaranteed 300mA continuous load current with a low 100mV dropout. The high-accuracy (±0.5%) output voltage is preset to an internally trimmed voltage in the +0.75V to +3.0V range. An active-low, open-drain reset output remains asserted for at least 2.2ms (MAX1963A) or 70ms (MAX1976A) after the output voltage reaches regulation. These devices are offered in thin SOT23 and thin DFN packages. An internal pMOS pass transistor allows the low supply current to remain independent of load and dropout voltage, making these devices ideal for portable battery-powered equipment.ApplicationsCellular/Smart/PDA PhonesDSC, CD/MP3 PlayersNotebook/Handheld ComputersPCMCIA Cards

The MAX1963A/MAX1976A low-dropout linear regulators operate from a +1.62V to +3.6V supply and deliver a guaranteed 300mA continuous load current with a low 100mV dropout. The high-accuracy (±0.5%) output voltage is preset to an internally trimmed voltage in the +0.75V to +3.0V range. An active-low, open-drain reset output remains asserted for at least 2.2ms (MAX1963A) or 70ms (MAX1976A) after the output voltage reaches regulation. These devices are offered in thin SOT23 and thin DFN packages. An internal pMOS pass transistor allows the low supply current to remain independent of load and dropout voltage, making these devices ideal for portable battery-powered equipment.ApplicationsCellular/Smart/PDA PhonesDSC, CD/MP3 PlayersNotebook/Handheld ComputersPCMCIA Cards

The LTC3772 is a constant frequency current mode step-down DC/DC controller in a low profile 8-lead SOT-23 (ThinSOT™) and a 3mm × 2mm DFN package. The No RSENSE™ architecture eliminates the need for a current sense resistor, improving efficiency and saving board space.The LTC3772 automatically switches into Burst Mode operation at light loads to increase efficiency at low output current. It consumes only 40µA of quiescent current under a no-load condition.The LTC3772 incorporates an undervoltage lockout feature that shuts down the device when the input voltage falls below 2V. To maximize the runtime from a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550kHz allows the use of a small inductor and capacitors. An internal soft-start smoothly ramps the output voltage from zero to its regulation point. Burst Mode LTC3772 Yes LTC3772B No Applications 1- or 2-Cell Li-Ion Battery-Powered Applications Wireless Devices Portable Computers Distributed Power Systems

The LTC4216 is a positive low voltage Hot Swap™ controller that allows a board to be safely inserted and removed from a live backplane. It controls load voltages ranging from 0V to 6V and isolates a severe fault with instantaneous analog current limiting.An internal high side switch driver controls the gate of an external N-channel MOSFET. An adjustable soft-start limits the rate of change of the inrush current at start-up for a large load capacitor. Together with an analog current limit amplifier, an electronic circuit breaker with adjustable response time provides dual level overcurrent protection. No external gate capacitor is required for the analog current limit loop compensation.The FB pin monitors the output supply voltage and signals the RESET output pin. An ON pin provides on/off control and a FAULT pin indicates the fault status. The LTC4216 is available in the 10-lead MSOP and 12-lead (4mm × 3mm) DFN packages.Applications Electronic Circuit Breaker Live Board Insertion and Removal Industrial High Side Switch/Circuit Breaker Optical Networking