Cavli Wireless C100QM/C10QM Hardware Manual
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than 2A peak, which will cause a large ripple on the power supply. If the instantaneous
voltage drop causes the VBAT supply voltage to be too low. Or the supply current is
insufficient and the module may shut down or restart. In order to ensure the normal
operation of the module, all power pins and ground pins must be connected and provide
sufficient power supply capability.
Figure 3-2 Burst current supply voltage drop for GSM TDMA network
Under the premise of ensuring that the VBAT power supply is sufficient, two
470uF/6.3V tantalum capacitors can be connected in parallel with the power input, and
then 10pF, 33pF, 0.1uF, 1uF ceramic capacitors.
Figure 3-3 VBAT power supply
3.3.2 Power reference circuit
The actual design of the power circuit can use a switching DC power supply or a linear
LDO power supply to design the VBAT power supply. Both design circuits need to supply
enough current. Refer specifically to the following circuit design: