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2022-09-24 22:26:30
LT1508 - Power Factor and PWM Controller (Voltage Mode)
Description The LT®1508 is a general-purpose off-line complete solution for switching power supplies using active power factor correction. The PFC part is the same, the LT1248's PFC de-en/sync controller, removed because the pin PFC and PWM are synchronized internally. The voltage mode PWM section (LT1509 is the current mode copy) contains all the primary side functions to convert the PFC preregulated high voltage output to the isolated low voltage output. The duty cycle of the PWM is internally limited to 47% (up to 50%) to prevent transformer saturation. When the PWM soft-start begins, the PFC output voltage reaches the preset. In the brief event of line loss, the PWM will be turned off when the PFC output drops below 73% of the voltage setpoint.
Features
PFC and PWM single-chip solutions run simultaneously at up to 300kHz
99% Over 20:1 Load Power Factor Current Range Voltage Mode PWM
Dedicated overvoltage protection (OVP pin) for transient overvoltage protection
Minimum Line Current Deadband Typical 250mA Startup Supply Current Line Switching Noise Filter Low Quiescent Current: 13mA Fast 1.5A Peak Current Gate Driver Independent Soft Start Control...