ICB2FL03G Datasheet, PDF (30/60 Pages) Infineon Technologies AG – 2nd Generation FL Controller for Fluorescent Lamp Ballasts

ICB2FL03G
Controller for Fluorescent Lamp Ballasts
Functional Description
2.6.2 Capacitive Load 2 (Overcurrent / Operation below Resonance)
A capacitive load 2 operation is detected if the voltage at the LSCS pin drops below a second threshold of
V_LSCS = –50 mV directly before the high side MOSFET is turned on or exceeds a third threshold of V_LSCS = 2.0 V
during ON switching of the high side MOSFET. If this overcurrent is present for longer than 620 μs, the IC triggers
a latched power-down mode after trying a single restart. The controller keeps monitoring the status continuously
until an adequate load is present e.g. a new lamp is inserted; then the IC changes to normal operation.
Normal Operation
Capacitive Load 2 (Over Current )
VDSLS
I_DSLS
VGateHS
V_GateLS
VLSCS
+ 2.0 V
V_DSLS
IDSLS
V_GateHS
VGateLS
V_LSCS
+ 2.0 V
- 50 mV
- 50 mV
t_{CAPLOAD 2}
Figure 23 Capacitive Mode 2 – Operation with Overcurrent
tCAPLOAD 2
2.6.3 Adjustable Self-adapting Dead Time
The dead time between the turn OFF and turn ON of the half-bridge drivers is adjustable (C16, see Figure 3) and
is detected via a second threshold (–50 mV) of the LSCS voltage. The range of the dead time adjustment is 1.05 μs
up to 2.1 μs during all operating modes. The start of the dead time measurement is the OFF switching of the high
side MOSFET. The end of the dead time measurement is when V_LSCS drops for longer than typically 200 ns
(internal fixed propagation delay) below –50 mV. This time will be stored (stored dead time) and the low side gate
driver switches ON. The high side gate driver turns ON again after OFF switching of the low side switch and the
stored dead time.
V_DSLS
Normal Operation in RUN Mode
VLSCS = -50mV
Gate LS
V_LSCS
END of Dead Time
Measurement
Gate HS
START of Dead Time
Measurement
Dead Time
200 ns
Propagation Delay
Dead Time
Stored Dead Time
Stored Dead Time
Figure 24 Dead Time of ON and OFF of the Half-Bridge Drivers
Final Data Sheet
30
V1.1, 2013-08-14