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RD0802

Figure 5.5: Inductor saturation: CH1 is the LO voltage, CH2 is the VS voltage, CH3 is the current

through the resonant inductor, and CH4 is the voltage across the lamp

Figure 5.6 shows the VS voltage and the voltage across the lamp when the IC undergoes

reset with a lamp exchange. When the lamp is removed, crest factor protection is

triggered, and the IC enters the Fault mode and shuts down. Since the lamp is removed,

LO pins is pulled above VLOSD+, and the IC goes to UVLO mode. When the lamp is re-

inserted, the IC goes back to the Preheat / Ignition mode, and the half-bridge starts to

oscillate again.

Figure 5.6: Lamp exchange: CH1 is the LO voltage, CH2 is the VS voltage, and CH4 is the

voltage across the lamp