The LT1737 is a monolithic switching regulator controller specifically designed for the isolated flyback topology. It drives the gate of an external MOSFET and is generally powered from a DC supply voltage. Output voltage feedback information may be supplied by a variety of methods including a third transformer winding, the primary winding or even direct DC feedback (see Applications Information). Its gate drive capability, coupled with a suitable external MOSFET and other power path components, can deliver load power up to tens of Watts.The LT1737 has a number of features not found on other isolated flyback controller ICs presently available. By utilizing current mode switching techniques, it provides excellent AC and DC line regulation. Its unique control circuitry can maintain regulation well into discontinuous mode in most applications. Optional load compensation circuitry allows for improved load regulation. An optional undervoltage lockout pin halts operation when the application input voltage is too low. An optional external capacitor implements a soft-start function.Applications Isolated Flyback Switching Regulators Medical Instruments Instrumentation Power Supplies

Demonstration Circuit 425B is a constant-frequency synchronous Buck-Boost converter using the LTC3440. The input range is from 2.5V to 5.5V, making it ideal for single-cell lithium-ion or three-cell NiCd/NiMH battery applications. For 2.7V minimum input voltage, this converter can provide up to 600mA load current. The output voltage is set at 3.3V. A different output voltage in the range of 2.5V to 5.5V can be obtained by changing one of the feedback resistors.

Demonstration circuit 438 is a triple phase, single output synchronous buck converter featuring the LTC3731CG. This circuit can be used for desktop computers and servers, notebook computers and other high output current DC/DC converters. The output voltage can be configured for either 2.5V or 1.8V and the maximum load current is 60A. The input voltage range of DC438 is 9V to 14V.

Demonstration circuit 447 is a step-down converter featuring the LTC3728EUH regulator. The PolyPhase® dual output controller LTC3728EUH drives two high current synchronous buck converters. Input is 5V–14V, output 1 is 2.5V with loads up to 13A and output 2 is 1.8V with loads up to 13A. For applications with input voltage less than 5V, DC447 includes a circuit footprint on the bottom side to provide a 5V bias power supply.

DC450A: Demo Board for LTC3717 Wide Operating Range, No RSENSE Step-Down Controller for DDR/QDR Memory Termination.

DC480A-F: Demo Board for the LTC3405A 1.5MHz, 300mA Synchronous Step-Down Regulator in ThinSOT.

Demonstration circuit 486B is a dual Smart Battery PowerPath and charger controller featuring the LTC1760. The input voltage is 12 to 20V. The charger output voltage is programmed SMBus serial interface. The maximum charge current is 4A. The demo board has been optimized to work with 2, 3 and 4- Cell Li-ion battery packs. A jumper is provided to select trip for low battery voltage (LOBAT), VLIMIT (VLIM), and ILIMIT (ILIM). The LTC1760 follows the Smart Battery Standards for the Smart Battery System Manager (SBSM) specification.

Demonstration circuit DC500 is a constant-frequency step-down converter, using the various versions (fixed output/adjustable output/Burst Mode/Burst Mode defeated) of the LTC3406 or LTC3406B monolithic synchronous buck regulators. The DC500 has an input voltage range of 2.7V to 5.5V, and is capable of delivering up to 600 mA of output current at minimum input voltage of 3V. The DC500A-A features the adjustable output, Burst Mode-capable LTC3406 with the output voltage set to 1.2V.

Demonstration circuit 501 is high power, high voltage, and high efficiency DC/DC buck converter featuring the LTC3703. This is a general-purpose high voltage DC to DC with an input voltage range of 20V to 72V. The board is optimized for positive 48V input operation with high voltage surges up to 72VDC allowed. The limiting factor is the LTC3703 GN16 package that will not meet UL/CSA/IEC60950 clearance and creepage distance requirements above the SELV 60VDC maximum due to pin spacing. If the user wishes to support higher continuous input voltages or compliance to 60950, the LTC3703 is offered in a G-28 pin package. See Data Sheet. However, for the purposes of evaluation, the board will work reliably up to 72V. The maximum continuous current in free air is 4A. 6A is permissible with some forced air cooling. The output voltage is programmed with a voltage divider and configured for 12V.

Demonstration circuit DC512B is a single battery switching step-down charge controller featuring the LTC4100. The recommended input power is 15 to 20V at 3.5A. A two-position jumper allows choice of protected output voltage range suitable for 3- and 4-Cell Li-ion batteries. Removal of the jumper allows full output voltage range. The maximum charge current is 4A. The demo board is initially configured for 12.6V at 3A for popular 3-cell Li-ion battery packs. LTC4100 will automatically charge a Smart Battery to termination as soon as input power is applied with a battery connected prior to power up. A VOUT pin automatically provides power to the system load from the wall adapter or battery. Status LEDs are provided for CHG, ACP, SMBALERT and SMBus activity.