特点
High Efficiency Over Wide Load Current Range
±0.8% Output Voltage Accuracy
Dual N-Channel MOSFET Synchronous Drivers
Pulse Transformer Synchronization
Optocoupler Feedback Driver
Programmable Current Limit Protection
±5% Margin Output Voltage Adjustment
Adjustable Overvoltage Fault Protection
Power Good Flag
Auxiliary 3.3V Logic Supply
Available in 16-Lead SSOP and SO Packages
典型应用
描述
The LTC?1698 is a precision secondary-side forward converter controller that synchronously drives external N-channel MOSFETs. It is designed for use with the LT?3781 primary-side synchronous forward converter controller to create a completely isolated power supply. The LT3781 synchronizes the LTC1698 through a small pulse transformer and the LTC1698 drives a feedback optocoupler to close the feedback loop. Output accuracy of ±0.8% and high efficiency over a wide range of load currents are obtained.
The LTC1698 provides accurate secondary-side current limit using an external current sense resistor. The input voltage at the MARGIN pin provides ±5% output voltage adjustment. A power good flag and overvoltage input are provided to ensure proper power supply conditions. An auxiliary 3.3V logic supply is included that supplies up to 10mA of output current.