The LT1952/-1 is a single switch forward controller with active transformer reset that provides timing signals to the secondary-side LTC3900 synchronous rectifier driver. The LT4430 is a secondary-side optodriver with a precision reference voltage that completes the tightly regulated isolated forward converter circuit. The LTC3900 and LT4430 are specified to a maximum operating junction temperature of 150°C. This type of forward converter design is well suited for 12 V, 24 V and 48 V nominal input voltages, commonly found in telecom, datacom, industrial and military/aerospace applications.
The LT1952/-1 includes all of the features necessary to implement an active clamp transformer reset, enabling higher efficiencies and greater power densities compared to conventional catch winding or resonant reset techniques. Two control outputs are provided: the main power switch control and the active clamp switch control. Additional features include a fixed programmable operating frequency from 100 kHz to 500 kHz, synchronizable up to 750 kHz, selectable maximum duty cycle, adjustable synchronous timing delay, undervoltage lockout, a low 100 mV current sense threshold, leading edge blanking and programmable soft start.
The LT1952/-1MP is available in a SSOP-16 package and 1,000-piece pricing starts at $9.35 each. The LTC3900MP is available in an SO-8 package and 1,000-piece pricing starts at $7.00 each. The LT4430MP is available in a TSOT-23 package and 1,000-piece pricing starts at $5.12 each.
More information about the LT1952/-1, LTC3900 and LT4430 at