FSDH321, FSDL321
Comparison Between FSDM311 and FSDx321
Function
FSDM311
FSDx321
FSDx321 Advantages
Soft-Start
15mS
15mS
• Gradually increasing current limit
during soft-start further reduces peak
current and voltage component
stresses
• Eliminates external components used
for soft-start in most applications
• Reduces or eliminates output
overshoot
External Current Limit
not applicable
not applicable
Programmable of
• Smaller transformer
default current limit
• Allows power limiting (constant over-
load power)
• Allows use of larger device for lower
losses and higher efficiency.
• Reduced conducted EMI
Frequency Modulation
Burst Mode Operation
±1.5KHz @50KHz
±3.0KHz @100KHz
Yes-built into
controller
Yes-built into
controller
• Improve light load efficiency
• Reduces no-load consumption
• Transformer audible noise reduction
Drain Creepage at
Package
7.62mm
7.62mm
• Greater immunity to arcing as a result
of build-up of dust, debris and other
contaminants
7
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
