Hardware Development Guide of Module Product
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50
MF206A
The over-current capability requirement of DC/DC switching power supply need to be above 3A, for
example,ZI1153, AAT2138 and so on.
Input voltage range of ZI1153 is: 2.5
~
5.5V
,
output voltage range of ZI1153 is from 0.6V to VIN( input
voltage).
Input voltage range of AAT2138is: 2.7
~
5.5V
,
output voltage range of AAT2138 is from 3.3
~
5.5V.
As shown in the Figure below, use DC/DC switching power supply ZI1153 as the buck chip. Place a tantalum
capacitor of 330
μ
F at the input of the chip. Place a 2200
μ
F capacitor or place several 330
μ
F tantalum
capacitors in parallel. This circuit fully meets the module power requirements. (If the user’s PCB size is limited,
the output of buck chip can place three more 330
μ
F tantalum capacitors of which the total capacity is more than
1000
μ
F)
Figure 4–3 DC/DC Switching Power Supply
Vin=5V
Vout=3.8V
Option two:
Use LDO as the buck chip. The over-current capability of LDO is above 3A. As the poor transient response of
linear regulator, large capacitors should be placed at the input and output of LDO. The output of LDO, place a
capacitors above 2000
μ
F. The reference power supply circuit design with LDO is as shown in Figure below.