Demonstration circuit 1725A features LT3759 in a 485kHz boost converter, designed for a 5V/2A output from a 1.8V to 4.5V input. The LT3759 is a current mode DC/DC Boost/SEPIC/Inverting controller operating over an input range of 1.6V to 42V. Thanks to a novel FBX pin architecture, the LT3759 allows both positive and negative output feedback voltages.

The LT3641 is a dual channel, current mode monolithic buck switching regulator with a power-on reset and a watchdog timer. Both regulators are synchronized to a single oscillator with an adjustable frequency (350kHz to 2.5MHz). At light loads, both regulators operate in low ripple Burst Mode? to maintain high effi ciency and low output ripple.The high voltage channel is a nonsynchronous buck with an internal 2.4A top switch that operates from an input of 4V to 42V and input transient protection to 55V. The low voltage channel operates from an input of 2.5V to 5.5V. Internal synchronous power switches provide high effi ciency without the need of external Schottky diode. Both channels have cycle-by-cycle current limit, providing protection against shorted outputs.The power-on reset and watchdog timeout periods are both adjustable using external capacitors. The window mode watchdog timer fl ags when the ?P pulses group too close together or too far apart.The LT3641 is available in a 28-pin 4mm ? 5mm QFN package and 28-pin TSSOP package. Both packages have an exposed pad for low thermal resistance.Applications Industrial Power Supplies Automotive Electronic Control Units

The LTC3226 is a 2-cell series supercapacitor charger with a backup PowerPath controller. It includes a charge pump supercapacitor charger with programmable output voltage, a low dropout regulator, and a power-fail comparator for switching between normal and backup modes.The constant input current supercapacitor charger is designed to charge two supercapacitors in series to a resistor-programmable output voltage from a 2.5V to 5.3V input supply. The charger input current limit is programmable by an external resistor at up to 315mA.The internal backup LDO is powered from the supercapacitors and provides up to 2A peak output current with an adjustable output voltage. When the input supply falls below the power-fail threshold, the LTC3226 automatically enters a backup state in which the supercapacitors power the output through the LDO. The input supply power-fail voltage level is programmed by an external resistor divider.Low input noise, low quiescent current and a compact footprint make the LTC3226 ideally suited for small, batterypowered applications. Internal current limit and thermal shutdown circuitry allow the device to survive a continuous short-circuit from the PROG or CPO pins to ground.Applications Smart Power Meters Battery-Powered Industrial/Medical Equipment 3.3V Solid-State Drives Industrial Alarms Data Backup Supplies Battery Hold-Up Supplies

Demonstration circuit 1739A-B is a 150W isolated forward converter with synchronous rectification featuring the LTC3765/LTC3766. This circuit demonstrates a high level of performance, efficiency, and small solution size attainable using these parts in an active-clamp-reset forward converter power supply. It operates at 240kHz and produces a regulated 12V, 12.5A output from an input voltage range of 18V to 72V, making it well suited for telecom, industrial, and other applications.

The LT1533 is a new class of switching regulator designed to reduce conducted and radiated electromagnetic interference (EMI). Ultralow noise and EMI are achieved by providing user control of the output switch slew rates. Voltage and current slew rates can be independently programmed to optimize switcher harmonic content versus efficiency. The LT1533 can reduce high frequency harmonic power by as much as 40dB with only minor losses in efficiency. The LT1533 utilizes a dual output switch current mode architecture optimized for low noise topologies. The IC includes two 1A power switches along with all necessary oscillator, control and protection circuitry. Unique error amp circuitry can regulate both positive and negative voltages. The internal oscillator may be synchronized to an external clock for more accurate placement of switching harmonics. Protection features include cycle by cycle current limit protection, undervoltage lockout and thermal shutdown. Low minimum supply voltage and low supply current during shutdown make the LT1533 well suited for portable applications. The part may also be forced into a 50% duty cycle mode for unregulated applications. The LT1533 is available in the 16-pin narrow SO package.Applications Precision Instrumentation Systems Isolated Supplies for Industrial Automation Medical Instruments Wireless Communications Single Board Data Acquisition Systems

DC1743A: Demo Board for LTM4613 EN55022B Compliant 36VIN, 15VOUT, 8A, DC/DC µModule Regulator.

DC1746A-B: Demo Board for LTM2881 Complete Isolated RS485/RS422 µModule Transceiver + Power.

The LTC1700 is a current mode synchronous step-up DC/DC controller that drives external N-channel and P-channel power MOSFETs using a constant frequency PWM architecture. Current limiting is provided by sensing the voltage drop across the main MOSFET, eliminating the need of a sense resistor. This No RSENSE? technique helps the LTC1700 maintain high efficiency at heavy loads while Burst Mode operation ensures high efficiency at light loads, thus providing high efficiencies over a wide range of load currents.The LTC1700 operates at a minimum input voltage as low as 0.9V. The device boasts a ?1.5% output voltage accuracy and consumes only 200?A of quiescent current. In shutdown, it only draws 10?A.To prevent inductor current runaway, the duty cycle is limited to 90%. Overvoltage protection is also provided which shuts both the external MOSFETs off when tripped.High constant operating frequency of 530kHz allows the use of small inductors and output capacitors. The LTC1700 can also be synchronized between 400kHz to 750kHz. Burst Mode operation is inhibited when the device is externally clocked or when the SYNC/MODE pin is pulled low to reduce noise and RF interference.Applications Cellular Telephones Wireless Modems RF Communications 2.5V to 3.3V, 2.5V to 5V Converters Battery-Powered Equipment Telecom/Network Systems

The LTC1734 is a low cost, single cell, constant-current/constant-voltage Li-Ion battery charger controller. When combined with a few external components, the SOT-23 package forms a very small, low cost charger for single cell lithium-ion batteries.The LTC1734 is available in 4.1V and 4.2V versions with 1% accuracy. Constant current is programmed using a single external resistor between the PROG pin and ground. Manual shutdown is accomplished by floating the program resistor while removing input power automatically puts the LT1734 into sleep mode. Both the shutdown and sleep modes drain near zero current from battery.Charge current can be monitored via the voltage on the PROG pin allowing a microcontroller or ADC to read the current and determine when to terminate the charge cycle. The output driver is both current limited and thermally protected to prevent the LTC1734 from operating outside of safe limits. No external blocking diode is required.The LTC1734 can also function as a general purpose current source or as a current source for charging nickel-cadmium (NiCd) and nickel-metal-hydride (NiMH) batteries using external termination. Charge Current Vfloat LTC1734 180mA to 700mA 4.1V or 4.2V LTC1734L 50mA to 180mA 4.2V Applications Cellular Telephones Handheld Computers Digital Cameras Charging Docks and Cradles Low Cost and Small Size Chargers Programmable Current Source

The LTC3201 is an ultralow noise, constant frequency, charge pump DC/DC converter specifically designed for powering white LEDs. The part produces a low noise boosted supply capable of supplying 100mA of output current. LED current is regulated for accurate and stable backlighting. A 3-bit DAC provides output current adjust for brightness control.Low external parts count (one small flying capacitor and three small bypass capacitors) and small MSOP-10 package size make the LTC3201 ideally suited for space constrained applications. An input noise filter further reduces input noise, thus enabling direct connection to the battery. High switching frequency enables the use of small external capacitors.The LTC3201 contains overtemperature protection and can survive an indefinite output short to GND. Internal soft-start circuitry also prevents excessive inrush current on start-up. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1?A.Applications White LED Backlighting Programmable Boost Current Source