AME5258 Datasheet, PDF (11/17 Pages) AMETHERM Circuit Protection Thermistors – 1.5MHz, 600mA Synchronous Buck Converter

AME
AME5258
VIN
3.3V to 5.5V
IN
SW
COUT
4.7µF
CER
AME5258
EN
FB
GND
2.2µH
22pF
960K
240K
VOUT
3V
COUT
10µF
CER
1.5MHz, 600mA
Synchronous Buck Converter
V_IN
3.6V to 5.5V
IN
SW
COUT
4.7µF
CER
AME5258
EN
FB
GND
2.2µH
22pF
887K
196K
VOUT
3.3V
C_OUT
10µ F
CER
Figure 8: 3V Step-Down Regulator
Figure 9: 3.3V Step-Down Regulator
PC Board Layout Checklist
When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the
AME5258. These items are also illustrated graphically in Figures 10 and Figures 11 . Check the following in your layout:
1. The power traces, consisting of the GND trace, the SW trace and the V_IN trace should be kept short, direct and wide.
2. Does the V_FB pin connect directly to the feedback resistors? The resistive divider R1/R2 must be connected between
the (+) plate of C_OUT and ground.
3. Does the (+) plate of CIN connect to V_IN as closely as possible? This capacitor provides the AC current to the internal
power MOSFETs.
4. Keep the switching node, SW, away from the sensitive V_FB node.
5. Keep the (-) plates of C_IN and C_OUT as close as possible.
V_IN
IN
SW
AME5258
EN
FB
+
C_IN
GND
-
L1
CFWD
R2
R1
VOUT
+
COUT
-
V_IN
IN
L1
SW
AME5258
EN
V_OUT
+
CIN
GND
-
VOUT
+
COUT
-
Figure 10: AME5258 Adjustable Voltage
Regulator Layout Diagram
Rev.A.05
Figure 11: AME5258 Fixed Voltage
Regulator Layout Diagram
11