bd9324efj ROHM Co. Ltd., bd9324efj Datasheet - Page 11

• Manufacturer Part Number: bd9324efj
• Description: Simple Step-down Switching Regulator With Integrated Compensation
• Manufacturer: ROHM Co. Ltd.

output capacitors, and then returns to the input capacitor through GND.
shotkey diode through GND.
Layout patterns.
great thermal conduction to the chip. So using the
GND plain as broad and wide as possible can help
thermal dissipation. And a lot of thermal via for
helping the spread of heat to the different layer is also
effective.
as possible to the VIN terminal.
connected FB and COMP away from SW pin.
capacitors should be placed close to SW pin as much
as possible.
・ The input capacitors should be connected as close
Two high pulsing current flowing loops exist in the buck regulator system.
The first loop, when FET is ON, starts from the input capacitors, to the VIN terminal, to the SW terminal, to the inductor, to the
The second loop, when FET is OFF, starts from the shotkey diode, to the inductor, to the output capacitor, and then returns to the
To reduce the noise and improve the efficiency, please minimize these two loop area.
Especially input capacitor, output capacitor and shotkey diode should be connected to GND plain.
PCB Layout may affect the thermal performance, noise and efficiency greatly. So please take extra care when designing PCB
・The thermal Pad on the back side of IC has the
・Keep sensitive signal traces such as trace
・The inductor, the shot key diode and the output
Layout Pattern Consideration
VIN
C
11/13
OUT
C
2 Current loop in Buck regulator system
IN
C
Di
V
IN
The example of PCB layout pattern
OUT
FET
L
VIN
SW
Di
SS
BST
VIN
SW
L
FET
C
OUT
COMP
GND
EN
FB
V
OUT