AN628 APPLICATION NOTE

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Figure 28.

Figure 29.

Figure 30.

Figure 31.

VDS = 100V/div.

IL2 = 2A/div.

IL2-VDS waveforms at SWITCH-ON

"Magnethic snubber effect"

Drain current slope control

IL2-VDS waveforms at SWITCH-OFF

Current

Drain voltage

Drain voltage snubber RCD effect

IL2-VDS waveforms at SWITCH-OFF and ON

Current

flowing

in the Voltage Clamp

Drain voltage

Recovery Peak current

Boost diode Anode voltage and IL2 Current

0V

Negative Voltage

for L2 demagnetization

Miscellaneous:

The 360W Demo Board is replacing a previous 200W version. It is possible to order this tool quoting the order

code EVAL4981A. The board comes with a CDROM containing the inherent documentation and a special pro-

gram dedicated to the ST PFC controllers (L4981 and L6561) that make it easy the design of these applications.