Advanced Analog Technology, Inc.
APPLICATION CIRCUIT FOR BACKLIGHT DIMMING
APPLICATION INFORMATION
Operation
AAT1501 is a simple white LED driver. It uses charge pump to generate output voltage 2 times larger
than input voltage and keeps the output voltage stable by using the comparator of the device. The current of
the white LED could be set by an external resistor.
Short Circuit Protection
AAT1501/A includes a current-limit circuit. Whenever excessive current is generated, the mechanism
takes over the output regulation circuit and reduces output current to a typical level of 150mA.
LED Current Setting
A LED current ( ILED _ ) is set by a resistor, as follows:
VO −VF
R _ =
ILED _
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台灣類比科技股份有限公司
Advanced Analog Technology, Inc
Page 9 of 15
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AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
