User's Manual

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H380-GL Hardware User Manual Page
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3.2.1 Power Supply
H380 module provides power supply by using +3.3V pin, and the power supply design is shown in Figure
3-2:
Figure 3-2 Power Supply Design
The filter capacitor design of power supply is as follows:
Recommended
Capacitance
Application
Description
220uF x 2
Voltage-stabilizing
capacitance
To reduce power supply fluctuation in the
operating process of the module, low ESR
capacitance shall be adopted

LDO or DC/DC power supply shall not be less
than 440uF capacitance
 Battery power supply can be reduced to
100~220uF capacitance
1uF,100nF
Digital signal noise
Filter the interference produced by clock and
digital signal
39pF,33pF
850,900 MHz band
Filter the RF interference of low band
18pF,8.2pF,6.8pF
1800/1900,2100,2500MHz
band
Filter the RF interference of middle/high band
(including third harmonic of low band)
The stable power supply ensures the normal operation of H380 module. In the design, it's should be noted
that the ripple of power supply shall be lower than 300mV. When the module is operating in GSM mode
(Burst transmit), the maximum operating current is up to 2A, and the power supply voltage shall not be
less than 3.135V; otherwise, the module may shut down or restart due to outage. The power supply limit
is shown in Figure 3-3: