BD9394FP Datasheet, PDF (14/31 Pages) Rohm – White LED Driver for large LCD Panels (DCDC Converter type)

BD9394FP, BD9394EFV
●LED current setting
Setting of LED output current “ILED” can be made by connecting a resistor RISET to the ISET pin.
cRISET vs. ILED current relation equation
R_ISET
=
7500
I _LED [mA]
[kΩ]
　
(NADIM=7~35V)
However, LED current setting should be made in the range of 30mA to 150mA.
[Setting example]
To set ILED current to 100mA, RISET resistance is given by the following equation:
R_ISET
=
7500 ₌ 7500
I _LED [mA] 100[mA]
= 75
[kΩ]
　
●DC/DC converter drive frequency setting
DC/DC converter drive frequency is determined by making RT resistance setting.
cDrive frequency vs. RT resistance (ideal) relation equation
R _RT
=
15000
f _SW [kHz ]
[kΩ]
where fsw = DC/DC converter oscillation frequency [kHz]
This equation has become an ideal equation without any correction item included.
For accurate frequency settings, thorough verification should be performed on practical sets.
[Setting example]
To set DC/DC drive frequency “fsw” to 200 kHz, RRT is given by the following equation:
R_RT
=
15000 ₌ 15000 _{= 75}
f _sw[kHz] 200[kHz]
[kΩ]
　
Datasheet
www.rohm.com
© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
14/28
TSZ02201-0F1F0C100180-1-2
09.Nov.2012 Rev.002