Quectel EC25 Hardware Design

LTE Module Series
EC25 Mini PCIe Hardware Design
EC25_Mini_PCIe_Hardware_Design Confidential / Released 23 / 42
In primary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising
edge. The PCM_SYNC falling edge represents the MSB. In this mode, PCM_CLK supports 128, 256, 512,
1024 and 2048kHz for different speed codecs. The following figure shows the timing relationship in
primary mode with 8kHz PCM_SYNC and 2048kHz PCM_CLK.
PCM_CLK
PCM_SYNC
PCM_DOUT
MSB
LSB
MSB
125us
1 2 256255
PCM_DIN
MSB
LSBMSB
Figure 6: Timing in Primary Mode
In auxiliary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising
edge; while the PCM_SYNC rising edge represents the MSB. In this mode, PCM interface operates with a
128kHz PCM_CLK and an 8kHz, 50% duty cycle PCM_SYNC only. The following figure shows the timing
relationship in auxiliary mode with 8kHz PCM_SYNC and 128kHz PCM_CLK.
PCM_CLK
PCM_SYNC
PCM_DOUT
MSB
LSB
PCM_DIN
125us
MSB
1 2 1615
LSB
Figure 7: Timing in Auxiliary Mode
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Quectel EC25 Specifications

General

Category	LTE Module
LTE TDD	B38/B40/B41
WCDMA	B1/B5/B8
GSM	850/900/1800/1900 MHz
Data rates	LTE Cat 4: 150 Mbps DL/50 Mbps UL
GNSS	GPS/GLONASS/BeiDou/Galileo/QZSS
Operating Temperature	-40°C to +85°C
Form Factor	LCC
Storage Temperature	-45°C to +90°C
SIM Interface	1.8V/3.0V
Antenna Interface	Main, Diversity, GNSS
LTE FDD	B1/B3/B5/B7/B8/B20
Interfaces	USB 2.0, UART, PCM, GPIO
Operating Voltage	3.3V - 4.3V
Protocols	TCP/IP, UDP, FTP, HTTP, HTTPS
Certifications	CE, FCC, PTCRB, GCF, RCM, IC