Adjustable Frequency Current Mode Flyback DC/DC Controller
The LTC®3805 is a current mode controller for flyback DC/DC converters designed to drive an N-channel MOSFET in high input and output voltage converter applications. Operating frequency and slope compensation can be programmed by external resistors. Programmable overcurrent sensing protects the converter from short-circuits. Soft-start can be programmed using an external capacitor and the soft-start capacitor also programs an automatic restart feature. The LTC3805 provides ±1.5% output voltage accuracy and consumes only 360µA of quiescent current during normal operation and only 40µA during micropower startup. Using a 9.5V internal shunt regulator, the LTC3805 can be powered from a high VIN through a resistor or it can be powered directly from a low impedance DC voltage of 9V or less. The LTC3805 is available in the 10-lead MSOP package and the 3mm × 3mm DFN package.
FeatureS:
● VIN and VOUT Limited Only by External Components
● Adjustable Slope Compensation n Adjustable Overcurrent Protection with Automatic Restart
● Adjustable Operating Frequency (70kHz to 700kHz) with One External Resistor
● Synchronizable to an External Clock
● ±1.5% Reference Accuracy
● Current Mode Operation for Excellent Line and Load Transient Response
● RUN Pin with Precision Threshold and Adjustable Hysteresis
● Programmable Soft-Start with One External Capacitor
● Low Quiescent Current: 360µA
● Small 10-Lead MSOP and 3mm × 3mm DFN
● Telecom Power Supplies
● 42V and 12V Automotive Power Supplies
● Isolated Electronic Equipment
(Picture:Pinout / Diagram)
