LTE Standard Module Series
EG21-G Mini PCIe Hardware Design
EG21-G_Mini_PCIe_Hardware_Design 19 / 54
3.2. Power Saving
3.2.1. Sleep Mode
EG21-G Mini PCIe is able to reduce its current consumption to a minimum value in sleep mode. There are
three preconditions must be met to make the module enter sleep mode.
Execute
AT+QSCLK=1
to enable sleep mode.
Ensure the DTR is kept at high level or be kept open.
The host’s USB bus, which is connected with the module’s USB interface, enters suspend state.
3.2.2. Airplane Mode
When the module enters airplane mode, the RF function will be disabled, and all AT commands related to
it will be inaccessible. For more details, please refer to
Chapter 3.10.3
.
3.3. Power Supply
The following table shows pin definition of VCC_3V3 pins and ground pins.
Table 6: Definition of VCC_3V3 and GND Pins
The typical supply voltage of EG21-G Mini PCIe is 3.3V. In the 2G network, the input peak current may
reach 2.7A during the transmitting time. Therefore, the power supply must be able to provide a rated
output current of 2.7A at least, and a bypass capacitor of no less than 470µF with low ESR should be
used to prevent the voltage from dropping. If the switching power supply is used to supply power to the
module, the power device and power supply routing traces of the switching power supply should avoid the
antennas as much as possible to prevent EMI interference.
The following figure shows a reference design of power supply where R2 and R3 are 1% tolerance
resistors and C3 is a low-ESR capacitor.
Pin Name
Pin No.
I/O
Power Domain
Description
VCC_3V3
2, 39, 41, 52
PI
3.0V~3.6V
Typically 3.3V DC supply
GND
4, 9, 15, 18, 21,
26, 27, 29, 34, 35,
37, 40, 43, 50
Mini card ground
