RT8251GSP Richtek USA Inc, RT8251GSP Datasheet - Page 13

• Manufacturer Part Number: RT8251GSP
• Description: IC DCDC CTRLR STP-DN 8SOP
• Manufacturer: Richtek USA Inc
• Type: Step-Down (Buck)r

Specifications of RT8251GSP

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.8 V ~ 15 V
• Current - Output: 5A
• Frequency - Switching: 570kHz
• Voltage - Input: 4.75 V ~ 24 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width) Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Layout Consideration
Follow the PCB layout guidelines for optimal performance
of the RT8251.
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DS8251-01 March 2011
LX node is with high frequency voltage swing and should
wide as possible.
Put the input capacitor as close as possible to the device
pins (VIN and GND).
be kept at small area. Keep analog components away
from the LX node to prevent stray capacitive noise pick-
up.
Keep the traces of the main current paths as short and
Figure 9. PCB Layout Guide for WQFN Package
GND
GND
The feedback components must be connected
as close to the device as possible.
Input capacitor must be placed
as close as to the IC as possible.
GND
VOUT
R1
VIN
VIN
VIN
1
2
3
4
C
IN
R2
C
16
R
5
C
C
15
GND
6
14
7
17
13
C
8
D
P
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}
}
12
11
10
Connect feedback network behind the output capacitors.
Keep the loop area small. Place the f eedback
components near the RT8251.
then connect the command node to the power ground
behind the output capacitors.
and Figure 10 for reference.
Examples of PCB layout guide are shown in Figure 9
9
Connect all analog grounds to a command node and
C
SW
SW
SW
BOOT
SS
R
C
S
S
C
OUT
L
C
BOOT
VOUT
SW should be connected
to inductor by Wide and
short trace. Keep sensitive
components away from
this trace.
RT8251
www.richtek.com
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