MP2214 – 16V, 4A, 600kHz SYNCHRONOUS STEP-DOWN CONVERTER
Output Capacitor Selection
3) Two input ceramic capacitors (2
x
The output capacitor keeps output voltage ripple
small and ensures regulation loop stable. The
output capacitor impedance shall be low at the
switching frequency. Ceramic capacitors with
X5R or X7R dielectrics are recommended. If
electrolytic capacitor is used, pay attention to
output ripple voltage, extra heating, and the
selection of feedback resistor R1 (refer to “Output
Voltage Setting” section) due to large ESR of
electrolytic capacitor. The output ripple ∆VOUT is
approximately:
(10μF~22μF)) are strongly recommended to be
placed on both sides of the MP2214DL package
and keep them as close as possible to the “IN”
and “GND” pins.
4) A RC low pass filter is recommended for VCC
supply. The VCC decoupling capacitor must be
placed as close as possible to “VCC” pin and
“GND” pin.
5) The external feedback resistors shall be
placed next to the FB pin. Keep the FB trace as
short as possible.
VOUTx(V − VOUT
)
1
IN
ΔVOUT
≤
x(ESR +
)
6) Keep the switching node SW short and away
from the feedback network.
V xfOSCxL
8xfOSCxC3
IN
External Schottky Diode
For this part, an external schottky diode is
recommended to be placed close to "SW" and
"GND" pins, especially when the output current is
larger than 2A.
With the external schottky diode, the voltage
spike and negative kick on "SW" pin can be
minimized; moreover, the conversion efficiency
can also be improved a little.
For the external schottky diode selection, it's
noteworthy that the maximum reverse voltage
rating of the external diode should be larger than
the maximum input voltage. As for the current
rating of this diode, 0.5A rating should be
sufficient.
Top Layer
PCB Layout Guide
PCB layout is very important to achieve stable
operation. It is highly recommended to duplicate
EVB layout for optimum performance. If change
is necessary, please follow these guidelines as
follows. Here, the typical application circuit is
taken as an example to illustrate the key layout
rules should be followed.
1) For MP2214, a PCB layout with >=4 layers is
recommended.
2) The high current paths (GND, IN and SW)
should be placed very close to the device with
short, direct and wide traces.
Inner Layer1
MP2214 Rev. 0.9
9/1/2010
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