ICB1FL01G Datasheet, PDF (15/38 Pages) Infineon Technologies AG – Smart Ballast Control IC for Fluorescent Lamp Ballasts

ICB1FL01G
Functional Description
1,80
1,70
1,60
1,50
1,40
1,30
1,20
1,10
1,00
0
50
100
150
200
250
Lamp Voltage / Sense Resistor [uA]
Figure 13 Maximum ratio of amplitudes versus sense current.
1,00
0,90
0,80
0,70
0,60
0,50
0,40
0,30
0,20
0
50
100
150
200
Lamp Voltage / Sense Resistor [uA]
250
Figure 14 Minimum ratio of amplitudes versus sense current.
3.5 Detection of capacitive mode operating conditions
If there happens a situation like an open resonant circuit (e.g. a sudden break of the tube) the voltage across the
resonant capacitor and current through the shunt of the low-side inverter MOSFET rise quickly. This event is
detected by inverter current limitation (1,6V) and results in shut down of the control. This status is latched as a
failure mode.
In another kind of failure the operation of the inverter may leave the zero voltage switching (ZVS) and move into
capacitive mode operation or into operation below resonance. There are two different levels for capacitive mode
detection implemented in the IC. A first criteria detects low deviations from ZVS (CapLoad1) and changes
operation into fault mode, if this operation lasts longer than 500ms. For CapLoad1 the same counter is used as
for the end-of-life evaluation.
Preliminary Datasheet Version 1.5
15
June 2005