特点
Wide Input Range: 3V to 25V
Programmable Volt-Second Clamp
Output Power Levels from 25W to 500W
Auxiliary Boost Converter Provides 10V Gate Drive from V
IN
as Low as 3V
Programmable Operating Frequency (100kHz to 500kHz) with One External Resistor
Programmable Slope Compensation
Programmable Leading Edge Blanking
±2% Internal 1.23V Reference
Accurate Shutdown Pin Threshold with Programmable Hysteresis
60ns Current Sense Delay
2.5V Auxiliary Reference Output
Synchronizable to an External Clock up to 1.5 ? f
OSC
Current Mode Control
Small 16-Pin SSOP Package
典型应用
典型应用
描述
The LT?1950 is a wide input range, forward, boost, flyback and SEPIC controller that drives an N-channel power MOSFET with few external components required.
A resistor programmable duty cycle clamp can be used to generate a volt-second clamp for forward converter applications. An internal boost switcher is available for creating a separate supply for the output gate driver, allowing 10V gate drive from input voltages as low as 3V. The LT1950’s operating frequency can be set with an external resistor over a 100kHz to 500kHz range and a SYNC pin allows the part to be synchronized to an external clock. Additional programmability exists for leading edge blanking and slope compensation.
A fast current sense comparator achieves 60ns current sense delay and the error amplifier is a true voltage mode error amplifier, allowing a wide range of compensation networks. An accurate shutdown pin with programmable hysteresis is available for undervoltage lockout and shutdown. The LT1950 is available in a small 16-Pin SSOP package.