IRPLLNR3 查看數據表（PDF） - International Rectifier
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IRPLLNR3 Datasheet PDF : 27 Pages
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IRPLLNR3
Resistors RVAC, RVDC and capacitor CVDC form a voltage divider/filter network, which is con-
nected to the VDC pin of the IR2167 and is used to determine if the line voltage falls below permis-
sible levels. This happens when the line voltage is cycled or possibly a brownout condition occurs.
The VDC pin of the IR2167 senses a fault if the voltage at the pin falls below 3 volts and shutdown of
the ballast occurs. The ballast remains shutdown until the voltage at the VDC pin rises above 5.1 volts.
At this time if there are no other fault conditions the ballast will go through a full Preheat, Ignition
Ramp and Run mode. As in the case of the SD pin of the IR2167, the VDC pin of the IR2167 is active
during all modes of operation of the ballast.
Lamp removal and autorestart
Resistors RPU, RSD and capacitor CSD1 form a divider/filter network which is used to detect an
open lower lamp filament and/or lamp replacement. Under normal conditions, the voltage across
CSD2 is close to zero. However, if the lower filament becomes open or the lamp is removed, the
voltage across CSD2 increases above the 5.1V threshold for the SD pin of the IR2167 and signals a
lamp removal condition, which in turn puts the ballast into UVLO mode. The ballast remains in the
UVLO mode until the lamp replacement is performed. If the lamp is replaced with a lamp with a good
lower filament, the voltage on the SD pin of the IR2167 drops back below the threshold and the ballast
will go through a restart. Line voltage cycling is also used to restart the ballast for all lamp fault
conditions. The ballast will go through a full Preheat, Ignition Ramp and Run modes any time a restart
is performed. Note that the SD pin of the IR2167 is active during all modes of operation.
Fault Mode
Fault mode is when the ballast driver is shutdown due to the detection of a lamp fault. Note that when
the ballast is in this Fault mode the power factor correction section of the ballast is also shutdown and
the bus voltage will drop to the non-boosted/unregulated level. There are several lamp fault conditions
that can put the ballast into the Fault mode. The lamp fault conditions detected include: near/below
resonance (under-current) detection, hard-switching detection, over-current detection (CS pin) and
end of life or no load detection (SD pin). Resistor RCS in the source lead of the low side MOSFET
(MHS) serves as the current sensing point for the half-bridge, which is used to detect these lamp fault
conditions. In operation when the half-bridge is oscillating, a voltage appears across RCS whenever
the low side MOSFET, MHS, is turned on or the high side MOSFET, MLS, is turned off. The magni-
tude of this voltage directly relates to the current in the lamp resonant circuit. Figure 11 shows the
voltage which appears across resistor RCS during normal Run mode conditions. Also shown in
Figure 11 are the gate drive signals for the low side MOSFET (LO pin) and the high side MOSFET
(HO-VS pin).
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