BD9123MUV_11 Datasheet, PDF (14/18 Pages) Rohm – Output 1.5A or Less High-efficiency Step-down Switching Regulator with Built-in Power MOSFET

BD9123MUV
●Cautions on PC Board layout
Technical Note
Fig.40 Layout diagram
① Lay out the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor Co closer to the
pin PGND.
② Lay out CITH and RITH between the pins ITH and GND as neat as possible with least necessary wiring.
※VQFN016V3030 has thermal PAD on the reverse of the package.
The package thermal performance may be enhanced by bonding the PAD to GND plane which take a large area of
PCB.
●Recommended components Lists on above application
Recommended components Lists
Symbol
Part
Value
Manufacturer
Series
L
Coil
4.7uH
TDK
VLF5014S-4R7M1R7
CIN
Ceramic capacitor
10uF
KYOCERA
CM316X5R106M10A
CO
Ceramic capacitor
22uF
KYOCERA
CM316B226M06A
CITH
Ceramic capacitor
1500pF
murata
GRM18 Series
RITH
Resistance
9.1kΩ
ROHM
MCR03 Series
Cf
Ceramic capacitor
0.1uF
murata
GRM18 Series
Rf
Resistance
100Ω
ROHM
MCR03 Series
※The parts list presented above is an example of recommended parts. Although the parts are sound, actual circuit
characteristics should be checked on your application carefully before use. Be sure to allow sufficient margins to
accommodate variations between external devices and this IC when employing the depicted circuit with other circuit
constants modified. Both static and transient characteristics should be considered in establishing these margins. When
switching noise is substantial and may impact the system, a low pass filter should be inserted between the VCC and
PVCC pins, and a schottky barrier diode or snubber established between the SW and PGND pins.
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14/17
2011.01 - Rev.A