Quectel EC21 Series User Manual

LTE Standard Module Series
EC21_Series_Hardware_Design
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
Sending data to module via USB will wake up the module.

When module has a URC to report, the module will send remote wake-up signals via USB bus to
wake up the host.
3.5.1.3. USB Application with USB Suspend/Resume and RI Function
If the host supports USB suspend and resume, but does not support remote wake-up function, the RI
signal is needed to wake up the host.
There are three preconditions to let the module enter sleep mode.
 Execute AT+QSCLK=1 to enable sleep mode.
 Ensure DTR is held at high level or keep it open.
 The host’s USB bus, which is connected with the module’s USB interface, enters suspend state.
The following figure shows the connection between the module and the host.
Figure 5: Sleep Mode Application with RI

Sending data to module via USB will wake up the module.

When module has a URC to report, RI signal will wake up the host.
3.5.1.4. USB Application Without USB Suspend Function
If the host does not support USB suspend function, USB_VBUS should be disconnected via an
additional control circuit to let the module enter sleep mode.

Execute AT+QSCLK=1 to enable sleep mode.

Ensure the DTR is held at high level or keep it open.

Disconnect USB_VBUS.

Quectel EC21 Series Specifications

General

Category	Control Unit
Form Factor	LCC
Operating Temperature	-40°C to +85°C
Storage Temperature	-45°C to +90°C
Power Consumption	TBD
Network Support (LTE TDD)	B38/B40/B41
Network Support (GSM)	850/900/1800/1900 MHz
Module Type	LTE Cat 1
Supply Voltage	3.3V
Interface	USB 2.0
SIM Interface	1.8V/3.0V
Data Rate (Downlink)	10 Mbps
Data Rate (Uplink)	5Mbps
Network Support (LTE FDD)	B1/B3/B5/B8/B20
GNSS	GPS/GLONASS/BeiDou
Certifications	CE, FCC, GCF, PTCRB

Summary

2 Product Overview

2.1. Frequency Bands and Functions

2.2. Key Features

Details key features of the EC21 series module, including power supply and transmission.

3 Application Interfaces

3.2. Pin Assignment

Visual representation of the EC21 series module's pin assignment (top view).

3.3. Pin Description

Detailed description of each pin's I/O type, function, and characteristics.

3.5. Power Saving

4 RF Specifications

4.1. Cellular Network

Details antenna interfaces, frequency bands, and operating frequencies for cellular network.

4.2. GNSS

Covers GNSS antenna interface, frequencies, and performance metrics.

4.4. Antenna Design Requirements

5 Electrical Characteristic and Reliability

5.1. Absolute Maximum Ratings

5.2. Power Supply Ratings

5.4. Power Consumption

Presents current consumption values for various operating states and conditions.

5.5. ESD

5.6. Thermal Dissipation

6 Mechanical Information

6.1. Mechanical Dimensions

Provides the physical dimensions and tolerances of the EC21 module.

6.2. Recommended Footprint

Offers a recommended PCB footprint for the EC21 series module.

7 Storage, Manufacturing and Packaging

7.2. Manufacturing and Soldering

Guides on manufacturing processes, soldering, and thermal profiles.