Analog Devices Inc./Maxim Integrated

The LT3574 is a monolithic switching regulator specifically designed for the isolated flyback topology. No third winding or opto-isolator is required for regulation. The part senses the isolated output voltage directly from the primary side flyback waveform. A 0.65A, 60V NPN power switch is integrated along with all control logic into a 16-lead MSOP package.The LT3574 operates with input supply voltages from 3V to 40V, and can deliver output power up to 3W with no external power switch. The LT3574 utilizes boundary mode operation to provide a small magnetic solution with improved load regulation.The output voltage is easily set with two external resistors and the transformer turns ratio. Off-the-shelf transformers are available for many applications.ApplicationsIndustrial, Automotive and Medical Isolated Power Supplies

The LT3580 is a PWM DC/DC converter containing an internal 2A, 42V switch. The LT3580 can be configured as either a boost, SEPIC or inverting converter. Capable of generating 12V at 550mA or –12V at 350mA from a 5V input, the LT3580 is ideal for many local power supply designs.The LT3580 has an adjustable oscillator, set by a resistor from the RT pin to ground. Additionally, the LT3580 can be synchronized to an external clock. The free running or synchronized switching frequency range of the part can be set between 200kHz and 2.5MHz.The LT3580 also features innovativeSHDNpin circuitry that allows for slowly varying input signals and an adjustable undervoltage lockout function.Additional features such as frequency foldback and soft-start are integrated. The LT3580 is available in tiny 3mm × 3mm 8-lead DFN and 8-lead MSOP packages.ApplicationsVFD Bias SuppliesTFT-LCD Bias SuppliesGPS ReceiversDSL ModemsLocal Power Supply