DT8211 View Datasheet(PDF) - Unspecified
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DT8211 Datasheet PDF : 10 Pages
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DMB Technology
DT8211
LCD Back Light Inverter Drive IC
10. Functional Description (Continued)
Protection (OLP, SCP)
Abnormal status is detected by IFB level. If IFB level goes under 0.75V, DT8211
became protection mode. This mode means that one or more of current feedback
levels is very low. To change to normal operating mode, IFB level must be higher
than 0.75V. In protection mode, a capacitor which is connected PROT pin is charged
by 0.5uA. If PROT pin is over 3.0V, DT8211 will shutdown the outputs. To restart
DT8211 after shutdown, EN or VCC must be low and go high. The time of protection
is as below.
TPROT [sec] = 6 ´106 ×C PROT
Striking Mode
Striking mode is a part of abnormal status. This mode is detected by IFB level and
ICMP level. If IFB level goes under 0.75V and ICMP level goes over 3.5V, DT8211
became striking mode. (Of course striking mode must be occurred in protection
mode.) This mode means lamp open status, so DT8211 try to increase output
voltage by shifting operating frequency. In this mode, RTS goes to 0V and burst
dimming signal is ignored. The striking frequency is decided as above description.
OVP (Over Voltage Protection)
OVP function is implemented by internal voltage error amplifier. The reference
voltage is 2.0V and in over voltage status, VFB pin is regulated as 2.0V.
Soft Start
After enabling DT8211, all capacitors which are connected to DT8211 are charged to
make startup. A capacitor which is connected to VCMP must be chosen as a large
value such as 100~300nF for soft start.
Gate Driver
DT8211 includes P channel and N channel gate drivers. The swing voltage of driver
output is approximately 12V and DT8211 can drive directly PowerFETs without
external component.
Rev1.1– 11 July 2008
© 2007 DMB Tech. All Rights Reserved
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