SC121ULTRT Semtech, SC121ULTRT Datasheet - Page 20

• Manufacturer Part Number: SC121ULTRT
• Description: IC BOOST SYNC 1.2A MLPD-6
• Manufacturer: Semtech
• Type: Step-Up (Boost)r

Specifications of SC121ULTRT

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 3.3V, 1.8 ~ 5 V
• Current - Output: 1.2A
• Frequency - Switching: 1.2MHz
• Voltage - Input: 0.7 ~ 4.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 6-MLPD-UT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: SC121ULTRTTR

Applications Information (continued)
PCB Layout Considerations
Poor layout can degrade the performance of the DC-DC
converter and can contribute to EMI problems, ground
bounce, and resistive voltage losses. Poor regulation and
instability can result.
The following simple design rules can be implemented to
ensure good layout:
•
•
Place the inductor and fi lter capacitors as close
to the device as possible and use short wide
traces between the power components.
Route the output voltage feedback path away
from the inductor and LX node to minimize
noise and magnetic interference.
L
X
Figure 4 — Layout Drawing
7.0mm
V
GND
IN
LX
IN
SC121
C
A suggested layout is shown in Figure 4.
IN
•
•
C
OUT
OUT
EN
FB
Maximize ground metal on the component side
to improve the return connection and thermal
dissipation. Separation between the LX node
and GND should be maintained to avoid cou-
pling capacitance between the LX node and the
ground plane.
Use a ground plane with several vias connecting
to the component side ground to further reduce
noise interference on sensitive circuit nodes.
GND
C
R
FB
2
(2
V
nd
R
layer)
1
OUT
5.2mm
SC121
20