bd9137muv ROHM Co. Ltd., bd9137muv Datasheet - Page 12

• Manufacturer Part Number: bd9137muv
• Description: High Efficiency Step-down Switching Regulator
• Manufacturer: ROHM Co. Ltd.

●BD9137MUV Cautions on PC Board layout
●Recommended components Lists on above application
※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.
① Lay out the input ceramic capacitor CIN closer to the pins PVCC and PGND, and the output capacitor Co closer to the pin
② Lay out CITH and RITH between the pins ITH and GND as neat as possible with least necessary wiring.
Symbol
C
R
C
PGND.
C
C
※ VQFN020V4040 (BD9137MUV) has thermal PAD on the reverse of the package.
Cf
Rf
L
ITH
ITH
BST
IN
O
The package thermal performance may be enhanced by bonding the PAD to GND plane which take a large area of
PCB.
Coil
Ceramic capacitor
Ceramic capacitor
Ceramic capacitor
Resistance
Ceramic capacitor
Resistance
Ceramic capacitor
Part
V
V
V
V
V
V
V
V
V
V
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
=1.0V
=1.2V
=1.5V
=1.8V
=2.5V
=1.0V
=1.2V
=1.5V
=1.8V
=2.5V
Fig.35 Layout diagram
1000 pF
0.1 uF
2.0uH
2.2uH
Value
22uF
22uF
10Ω
12/16
1500pF
1000pF
1000pF
5.6kΩ
6.8kΩ
6.8kΩ
8.2kΩ
560pF
560pF
12kΩ
Manufacturer
Sumida
Sumida
Murata
Murata
Murata
Murata
Murata
Murata
Murata
Murata
Murata
Rohm
Rohm
Rohm
Rohm
Rohm
Rohm
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CDR6D28MNP-2R0NC
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Series