BD6067GU

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Datasheet

Datasheet

TSZ02201-0G3G0C200080-1-2

© 2012 ROHM Co., Ltd. All rights reserved.

5.OCT.2012 Rev.001

www.rohm.com

●External components Selection Method

<<Constants in the standard circuit example>>

R1: Determines the LED current ILED at power ON.

<Recommended parts>

ILED (mA)

R1[Ω]

5

39

15

13

20

10

L1: Coil for boost. The recommended value is 22µH. be sure to use a sufficient DC current permissible value and a

sufficient low DC resistance coil.

<Recommended parts>

Inductance value

Model number/manufacturer

22µH

NR3015T220M / TAIYO YUDEN

CIN: Bypass capacitor of power supply. This capacitor must be provided to remove an instantaneous power supply noise for

stable voltage supply to this IC. To obtain good characteristics, the low ESR parts like the ceramics capacitor must be

used. The recommended capacitance is 1µF or more.

<Recommended parts>

Capacitance value

Model number/manufacturer

1.0µF

GRM188B11A105KA61B / MURATA

COUT: Output smoothing capacitor. The capacitance recommended for BD6067GU is 1.0µF.

<Recommended parts>

Capacitance value

Model number/manufacturer

1.0µF

UMK107C105KA-B / TAIYO YUDEN

When selecting capacitors for CIN and COUT, special care should be taken for rated voltage. The desirable rated

voltage is about double the voltage actually applied to the capacitor. When the margin for rated voltage is not sufficient,

the capacitance may be a half or less of the nominal value.

D1: Schottky barrier diode (SBD) for output rectification. To achieve high conversion efficiency, use a diode characterized

by of low Vf, low reverse leak and high current capacity.

<Recommended parts>

Model number/manufacturer

RB160M-40 / ROHM

●Recommended PCB layout

When a PCB designed, the power supply line should be wired in a way that the board impedance can be minimized. If

necessary, the bypass capacitor must be connected. In particular, pins around the DC/DC converter must be wired in such

a way that the wiring impedance can be minimized. In addition, when a DC/DC converter using a coil is used, it is

necessary to place the output capacitor COUT, coil L1, rectification diode D1 and bypass capacitor CIN near this IC and

keep the GND impedance low.

Figure 18. PCB Layout Image

GNDA

EN

VDAC

VIN

VFB

VOUT

SW

GND

CIN

COUT

To battery GND

To cell voltage source

L1