BD6067GU_11 Datasheet, PDF (24/30 Pages) Rohm – White Backlight LED Drivers for Small to Medium LCD Panels (Switching Regulator Type)

BD6067GU, BD6069GUT, BD6071HFN, BD6072HFN
Technical Note
►BD6069GUT, BD6072HFN
●Selection of external parts
Recommended external parts are as shown below.
When to use other parts than these, select the following equivalent parts.
・Coil
Value Tolerance Manufacturer
Product number
Size (mm)
W
L
22μH
±10% MURATA
LQH32CN220K53
2.5
3.2
22μH
±20% TDK
VLF3012AT220MR33
2.6
2.8
22μH
±20% Coil Craft
DO1608
4.45
6.6
22μH
±20% TDK
VLF3010AT220MR33
2.6
2.8
Please refer to the reference data of p.20 for the change in the efficiency when the coil is changed.
・Capacitor
Value
Manufacturer
<CIN>
1µF MURATA
<COUT>
1µF MURATA
Product number
GRM188B11A105K
GRM188B31E105K
Size (mm)
L
W
1.6
0.8
1.6
0.8
H
DCR (Ω)
1.55
0.71
1.2
0.66
2.92
0.37
1.0
1.30
Temperature range
H
0.8
-25deg~+85deg
0.8
-25deg~+85deg
・Resistor
Value Tolerance Manufacturer
Product number
<RFB>
24Ω
±1% ROHM
MCR006YZPF24R0
Size (mm)
L
W
H
0.6
0.3
0.23
The coil is the part that is most influential to efficiency. Select the coil whose direct current resistor (DCR) and current -
inductance characteristic is excellent. The BD6069GUTT/BD6072HFN is designed for the inductance value of 22µH. Do not
use other inductance value. Select a capacitor of ceramic type with excellent frequency and temperature characteristics.
Further, select Capacitor to be used for CIN/COUT with small direct current resistance, and pay sufficient attention to the
PCB layout shown in the next page.
●PCB Layout
In order to make the most of the performance of this IC, its PCB layout is very important. Characteristics such as efficiency
and ripple and the likes change greatly with PCB layout, which please note carefully.
To battery
power source
CIN
GNDA EN
TEST
VIN
VFB
RFB
VOUT
SW
GND
COUT
To battery GND
L1
GNDA
EN
TEST
VFB
RFB
To battery
CIN
power source
VIN
VOUT
COUT _L1
SW
GND
To battery GND
Fig.76 BD6069GUT PCB Layout Image
Fig.77 BD6072HFN PCB Layout Image
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2011.01 - Rev.C