ICB2FL01G Datasheet, PDF (24/56 Pages) Infineon Technologies AG – Smart Ballast Control IC for Fluorescent Lamp Ballasts

2^nd Generation FL-Controller for FL-Ballasts
Functional Description
The relationship between the extended PFC pulse width and the zero crossing detection current is
shown in Figure 19.
2.4.5 Optional THD Correction dedicated for DCM Operation
For applications with a wide input voltage range and / or for applications using a wide variation of the
power e.g. dimming, the application might work in the DCM (Discontinuous Conduction Mode). In
order to minimize the high order harmonics during DCM, the detection of the DCM should be as close
as possible at the point of inflection of the PFC drain source voltage shown in Figure 18. This can be
realized with an optional damping network (R4, D10 and Q4 from the AUX pin to the ZCD resistor
R13.
PFC Drain Source
Voltage
0
Voltage at PFC ₀
ZCD winding
with damping
CritCM
Detection
DCM
Detection
t
t
Output current
at Pin AUX in DCM
0
t
PFC Gate Source
Voltage
0
t
Figure 18: Signal Shapes with optional damping Figure 19: PFC ON Time Extension versus Zero
of oscillations during DCM operation of PFC
Crossing Current Signal
Figure 20: Optional Circuit for attenuating oscillations during DCM operation of PFC.
Datasheet
Page 24 of 56
ICB2FL01G
V1.2