AME5251A Datasheet, PDF (10/19 Pages) Analog Microelectronics – Dual 1A, 1.5MHz Synchronous Step-Down Converter

AME
AME5251A
Dual 1A, 1.5MHz Synchronous
Step-Down Converter
PC Board Layout Checklist
When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the
AME5251A. 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 R2/R1 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.
SW1, SW2 should be connected to inductor by wide and short trace .
Keep sensitive components away from this trace .
COUT2
VOUT2
C_{IN 2}
L2
R12
C11
R11
VOUT1
VIN2 1
SW 2
2
GND
3
FB1
4
NC1 5
EN1
6
AME5251A
GND
12 EN2
11 NC2
R21
10 FB2
R22
9 GND
L1
8 _SW1
7 VIN1
CIN1
R11, R12, R21, R22 and C 11,
C21 must be kept close to the
ICϗs FB pin to prevent noise
injection on the FB pin trace and
keeping far away from SW
node .
VOUT2
C21
VOUT 1
COU T1
NC 1, NC2 pin no
connect or connect
to GND.
The ground area must provide adequate heat
dissipating area to the thermal pad and using
multiple vias to help thermal dissipation .
C_IN1, C_IN2 should be placed
between V IN and GND as
close as possible .
Figure 7: AME5251A Adjustable Voltage Regulator Layout Diagram
10
Rev. A.04