FAN7310_05 Datasheet, PDF (8/12 Pages) Fairchild Semiconductor – LCD Back Light Inverter Drive IC

FAN7310
Open lamp regulation & open lamp protection : It is
necessary to suspend power stage operation if an open
lamp occurs, because the power stage has high gain.
When a voltage higher than 2V is applied to the OLR
pin, the part enters the regulation mode and controls
EA_OUT voltage to limit the lamp voltage by summing
105uA into the feedback node. At the same time, the
OLP capacitor, connected to the OLP pin, is charged by
the 1.4uA internal current source. Once reached to 2V,
IC enters shut down where all the output is high.
OUTPUT DRIVES: The four output drives are designed
so that switches A and B, C and D never turn on
simultaneously. The OUTA-OUTB pair is intended to
drive one half-bridge in the external power stage. The
OUTC-OUTD pair will drive the other half-bridge.
SYNC: This pin is used as the frequency synchroniza-
tion. The switching frequency can be synchronized with
an external control signal. The threshold voltage of this
pin is 1V. A resistor should be connected between this
pin and GND for the safe operation.
8