Power Supply; Power Supply Pins; Voltage Stability Requirements - Quectel EC21 Series Hardware Design

NOTE
1. The W_DISABLE# control function is disabled in firmware by default. It can be enabled by
AT+QCFG="airplanecontrol". For details of the command, see document [2].
2. The execution of AT+CFUN will not affect GNSS function.

3.6. Power Supply

3.6.1. Power Supply Pins

EC21 series 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 7: VBAT and GND Pins
Pin Name Pin No.
VBAT_RF 57, 58
VBAT_BB 59, 60
GND 8, 9, 19, 22, 36, 46, 48, 50–54, 56, 72, 85–112

3.6.2. Voltage Stability Requirements

The power supply range of the module is from 3.3–4.3 V. Make sure that the input voltage will never drop
below 3.3 V. The following figure shows the voltage drop during burst transmission in 2G network. The
voltage drop will be less in 3G and 4G networks.
EC21_Series_Hardware_Design
Description
Power supply for module's
RF part.
Power supply for module's
baseband part.
LTE Standard Module Series
Min. Typ. Max.
3.3 3.8 4.3
3.3 3.8 4.3
Unit
V
V
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