Product Info

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design
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3.5. Power Supply
3.5.1. Power Supply Pins
EC21 provides four VBAT pins for connection with the external power supply. There are two separate
voltage domains for VBAT.
 Two VBAT_RF pins for module’s RF part.
 Two VBAT_BB pins for module’s baseband part.
The following table shows the details of VBAT pins and ground pins.
Table 6: VBAT and GND Pins
Pin Name
Pin No.
Description
Min.
Typ.
Max.
Unit
VBAT_RF
57, 58
Power supply for module’s
RF part.
3.3
3.8
4.3
V
VBAT_BB
59, 60
Power supply for module’s
baseband part.
3.3
3.8
4.3
V
GND
8, 9, 19, 22, 36,
46, 48, 50~54,
56, 72, 85~112
Ground
-
0
-
V
3.5.2. Decrease Voltage Drop
The power supply range of the module is from 3.3V to 4.3V. Please make sure that the input voltage will
never drop below 3.3V. The following figure shows the voltage drop during burst transmission in 2G
network. The voltage drop will be less in 3G and 4G networks.
Figure 7: Power Supply Limits during Burst Transmission