•
48
•
64
•
96
Note:
The device uses 2 * Kp for calculations (see
Section 2.1.2 PFC compensation parameters
)
3.3.3
PFC MOSFET LEB
Size: 3 bits
Sets the PFC MOSFET minimum on-time (also called LEB, i.e. “Leading Edge Blanking”).
Available values are:
•
133 ns
•
167 ns
•
200 ns
•
233 ns
•
267 ns
•
333 ns
•
400 ns
•
467 ns
This time is used to filter the spike on the PFC_CS pin at the PFC MOSFET turn-on. During this time the PFC_CS
comparator output (THD improver) is ignored.
Use
Adjust the blanking time according to design requirements.
The middle value 267 ns can be used as a starting point and then, after looking at the PFC_CS waveform during
the PFC operation it can be adjusted.
3.3.4
PFC THD improver base
Size: 3 bits
Sets the base value for the ReCOT functionality (THD improver).
Available values are:
•
0 mV
•
2 mV
•
4 mV
•
6 mV
•
8 mV
•
10 mV
•
12 mV
•
14 mV
The parameter sets the PFC_CS comparator threshold.
Use
This parameter can be tuned to improve the THD of the system. Together with the “PFC THD improver gain”, this
parameter can be used to improve the distortion and power factor of the PFC observing the current waveform and
THD/PF measurements.
UM3002
PFC parameters
UM3002
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Rev 1
page 10/42