Quectel EC21 Mini PCIe Series Hardware Design page 22

29 GND
30 SMB_CLK
31 PETn0
32 SMB_DATA
33 PETp0
34 GND
35 GND
36 USB_D-
37 GND
38 USB_D+
39 3.3Vaux
40 GND
41 3.3Vaux
42 LED_WWAN#
43 GND
44 LED_WLAN#
45 RESERVED
46 LED_WPAN#
EC21_Mini_PCIe_Hardware_Design
GND
I2C_SCL DO
DTR DI
I2C_SDA IO
RESERVED
GND
GND
USB_DM IO
GND
USB_DP IO
VCC_3V3 PI
GND
VCC_3V3 PI
LED_WWAN# OC
GND
USIM_
DI
PRESENCE
1)
PCM_CLK IO
RESERVED
LTE Standard Module Series
EC21 Mini PCIe Hardware Design
Mini card ground
I2C serial clock
Sleep mode control
I2C serial data
Reserved
Mini card ground
Mini card ground
USB differential data (-)
Mini card ground
USB differential data (+)
3.0V~3.6V, typically 3.3V
DC supply
Mini card ground
3.0V~3.6V, typically 3.3V
DC supply
LED signal for indicating the
network status of the
module
Mini card ground
(U)SIM card insertion
detection
PCM clock signal
Reserved
Require
external
pull-up to
1.8V.
Require
external
pull-up to
1.8V.
Require
differential
impedance
of 90Ω.
Require
differential
impedance
of 90Ω.
Active low
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