LT1952-1 Datasheet | Linear Technology

.Data Sheet.in Features n n n n LT1952/LT1952-1 Single Switch Synchronous Forward Controller DESCRIPTION The LT®1952/LT1952-1 are current mode PWM controllers optimized to control the forward converter topology, using one primary MOSFET. The LT1952/LT1952-1 provide synchronous rectifier control, resulting in extremely high efficiency. A programmable Volt-Second clamp provides a safeguard for transformer reset that prevents saturation. This allows a single MOSFET on the primary side to reliably run at greater than 50% duty cycle for high MOSFET, transformer and rectifier utilization. The devices include soft-start for controlled exit from shutdown and undervoltage lockout. A precision 107m V current limit threshold, independent of duty cycle, bines with softstart to provide hiccup short-circuit protection. The LT1952 is optimized for micropower bootstrap start-up from high input voltages. The LT1952-1 allows start-up from lower input voltages. Programmable slope pensation and leading edge blanking allow optimization of loop bandwidth with a wide range of inductors and MOSFETs. Each device can be programmed over a 100k Hz to 500k Hz frequency range and the part can be synchronized to an external clock. The error amplifier is a true op amp, allowing a wide range of pensation networks. The LT1952/LT1952-1 are available in a small 16-pin SSOP package. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. n n n n n n n n n n n n n Synchronous Rectifier Control for High Efficiency Programmable Volt-Second Clamp Output Power Levels from 25W to 500W Low Current Start-Up (LT1952: 460μA; VIN On/Off = 14.25V/8.75V) (LT1952-1: 400μA; VIN On/Off = 7.75V/6.5V) True PWM Soft-Start Low Stress Short-Circuit Protection Precision 107m V Current Limit Threshold Adjustable Delay for Synchronous Timing Accurate Shutdown Threshold with Programmable Hysteresis Programmable Slope pensation...