FAN7318B Datasheet, PDF (21/24 Pages) Fairchild Semiconductor – LCD Backlight Inverter Drive IC

This protection is disabled by a pull-down resistor (a few
MΩ) between CMP and GND. If CMP voltage reaches
2.5V, CMP source current decreases to 2µA. Determine
a pull-down resistor value such that the whole of this
current can flow through the resistor. If so, CMP-high
protection can be disabled, as shown Figure 63. This
protection is disabled in striking mode to ignite the
lamps reliably.
Figure 60. SLP in Burst Dimming Mode
Applying voltage higher than 2.5V to the ENA pin
disables SLP. Applying voltage lower than 2.1V to the
ENA pin enables SLP.
Figure 63. CMP-High Protection Disable by a Pull-
Down Resistor
Thermal Shutdown
The IC provides the function to detect abnormal over-
temperature. If the IC temperature exceeds
approximately 150°C, the thermal shutdown triggers.
Figure 61. Short-Lamp Protection Disable in DCR
Mode
CMP-High Protection
If CMP is more than 3.5V for a time predetermined by
the TIMER pin capacitor and a internal current source of
50µA in normal mode, the IC is shut down, as shown in
Figure 62.
Figure 62. CMP-High Protection
© 2009 Fairchild Semiconductor Corporation
FAN7318B • 1.0.0
21
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