DS6257A Datasheet, PDF (14/15 Pages) Richtek Technology Corporation – 6A, 18V, 500kHz, ACOTTM Step-Down Converter

RT6257A/B
Layout Considerations
Follow the PCB layout guidelines for optimal performance
of the device.
 Keep the traces of the main current paths as short and
wide as possible.
 Put the input capacitor as close as possible to VIN pin.
 LX node is with high frequency voltage swing and should
be kept at small area. Keep analog components away
from the LX node to prevent stray capacitive noise pickup.
 Connect feedback network behind the output capacitors.
Keep the loop area small. Place the feedback
components near the device.
 Connect all analog grounds to a common node and then
connect the common node to the power ground behind
the output capacitors.
 An example of the RT6257A/B PCB layout guide is
shown in Figure 8 for references.
The feedback components must be
connected as close to the device as possible.
The R_EN component must
be connected to V_IN.
Suggestion layout trace
wider for thermal.
V_OUT
R1
R2
FB
V_IN ^REN
EN
C_OUT
C_OUT
V_OUT
6 _BOOT
C_B
L
2
5 _LX
Suggestion layout trace
wider for thermal.
GND 3 4 VIN
C_IN
C_IN
Keep sensitive components away
from this trace. Suggestion layout
trace wider for thermal.
LX should be connected to inductor by
Wide and short trace. Keep sensitive
components away from this trace.
Suggestion layout trace wider for thermal.
Input capacitor must be placed as close
to the IC as possible. Suggestion layout
trace wider for thermal.
Figure 8. PCB Layout Guide
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is a registered trademark of Richtek Technology Corporation.
DS6257A/B-00 September 2016