Product Info

LTE Module Series
EG21-G MINIPCIE Hardware Design
EG21-G_MINIPCIE_Hardware_Design 18 / 48
1. Keep all NC, reserved and unused pins unconnected.
2.
1)
The digital audio (PCM) function is only supported on Telematics version.
3.
2)
Module’s pin3 and pin5 are prohibit pull up to high level before startup.
3.3. Power Supply
The following table shows pin definition of VCC_3V3 pins and ground pins.
Table 5: Definition of VCC_3V3 and GND Pins
The typical supply voltage of EG21-G MINIPCIE 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 enough
current, and a bypass capacitor of no less than 470µF with low ESR should be used to prevent the
voltage from dropping.
The following figure shows a reference design of power supply. The precision of resistor R2 and R3 is 1%,
and the capacitor C3 needs a low ESR.
LDO_IN
C1
C2
MIC29302WU U1
IN
OUT
EN
GND
ADJ
2 4
1 3 5
VCC_3V3
100nF
C3
470uF
C4
100nF
R2
82K 1%
47K 1%
R3
470uF
470R
51K
R4
R1
MCU_POWER
_ON/OFF
47K
4.7K
R5
R6
C5
C6
33pF
10pF
TVS
D1
Figure 3: Reference Circuit of Power Supply
Pin No.
Pin Name
I/O
Power Domain
Description
2, 39, 41, 52
VCC_3V3
PI
3.0V~3.6V
3.3V DC supply
4, 9, 15, 18, 21,
26, 27, 29, 34, 35,
37, 40, 43, 50
GND
Mini card ground
NOTES