Quectel EC20 Hardware Manual

EC20 Mini PCIe

Hardware Design

LTE Module Series

Rev. EC20_Mini_PCIe_Hardware_Design_V1.0
Date: 2015-02-28

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Quectel Wireless Solutions Co., Ltd.

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Tel: [phone]
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GENERAL NOTES

QUECTEL OFFERS THIS INFORMATION AS A SERVICE TO ITS CUSTOMERS. THE INFORMATION
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TO ENSURE THE QUALITY OF THE INFORMATION IT MAKES AVAILABLE. QUECTEL DOES NOT
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Copyright © Quectel Wireless Solutions Co., Ltd. 2015. All rights reserved.

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About the Document

History

Revision

Date

Author

Description

1.0

2015-02-28

Radom XIANG/
Mike ZHANG

Initial

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Contents

About the Document ................................................................................................................................... 2

Contents ....................................................................................................................................................... 3

Table Index ................................................................................................................................................... 5

Figure Index ................................................................................................................................................. 6

1 Introduction .......................................................................................................................................... 7

1.1. Safety Information...................................................................................................................... 8

2 Product Concept .................................................................................................................................. 9

2.1. General Description ................................................................................................................... 9

2.2. Description of Product Series .................................................................................................... 9

2.3. Key Features ........................................................................................................................... 10

2.4. Functional Diagram ................................................................................................................. 12

3 Application Interface ......................................................................................................................... 13

3.1. General Description ................................................................................................................. 13

3.2. EC20 Mini PCIe Interface ........................................................................................................ 13

3.2.1. Definition of Interface ..................................................................................................... 13

3.2.2. Pin Assignment .............................................................................................................. 16

3.3. Power Supply ........................................................................................................................... 17

3.4. USIM Card Interface ................................................................................................................ 18

3.5. USB Interface .......................................................................................................................... 19

3.6. UART Interface ........................................................................................................................ 20

3.7. PCM and I2C Interface ............................................................................................................ 22

3.8. Control Signals ........................................................................................................................ 24

3.8.1. RI Signal ......................................................................................................................... 25

3.8.2. DTR Signal ..................................................................................................................... 25

3.8.3. W_DISABLE# Signal ...................................................................................................... 25

3.8.4. PERST# Signal .............................................................................................................. 26

3.8.5. LED_WWAN# Signal ..................................................................................................... 26

3.9. Antenna Interface .................................................................................................................... 27

4 Electrical and Radio Characteristics ............................................................................................... 28

4.1. General Description ................................................................................................................. 28

4.2. Power Supply Requirements ................................................................................................... 28

4.3. IO Requirements ...................................................................................................................... 29

4.4. RF Characteristics ................................................................................................................... 29

4.5. GNSS Receiver ....................................................................................................................... 30

4.6. ESD Characteristics ................................................................................................................ 31

5 Mechanical Dimensions .................................................................................................................... 32

5.1. General Description ................................................................................................................. 32

5.2. Mechanical Dimensions of EC20 Mini PCIe ............................................................................ 32

5.3. Standard Dimensions of Mini PCI Express ............................................................................. 33

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5.4. Packaging ................................................................................................................................ 34

6 Appendix Reference .......................................................................................................................... 35

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Table Index

TABLE 1: DESCRIPTION OF EC20 MINI PCIE ................................................................................................ 10

TABLE 2: KEY FEATURES OF EC20 MINI PCIE ............................................................................................. 10

TABLE 3: DEFINITION OF IO PARAMETERS .................................................................................................. 13

TABLE 4: DESCRIPTION OF PIN ..................................................................................................................... 14

TABLE 5: VCC_3V3 AND GND PIN DEFINITION ............................................................................................ 17

TABLE 6: USIM PIN DEFINITION ..................................................................................................................... 18

TABLE 7: USB PIN DEFINITION ....................................................................................................................... 19

TABLE 8: PIN DEFINITION OF THE UART INTERFACE ................................................................................. 20

TABLE 9: PCM AND I2C PIN DEFINITION ....................................................................................................... 22

TABLE 10: CONTROL SIGNAL PIN DEFINITION ............................................................................................ 24

TABLE 11: RADIO OPERATIONAL STATES ..................................................................................................... 25

TABLE 12: INDICATION OF NETWORK STATUS ............................................................................................ 26

TABLE 13: POWER SUPPLY REQUIREMENTS .............................................................................................. 28

TABLE 14: IO REQUIREMENTS ....................................................................................................................... 29

TABLE 15: OUTPUT POWER OF CONDUCTED RF ....................................................................................... 29

TABLE 16: CONDUCTED RF RECEIVING SENSITIVITY ................................................................................ 30

TABLE 17: ESD CHARACTERISTICS .............................................................................................................. 31

TABLE 18: RELATED DOCUMENTS ................................................................................................................ 35

TABLE 19: TERMS AND ABBREVIATIONS ...................................................................................................... 35

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Figure Index

FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 12

FIGURE 2: PIN ASSIGNMENT ......................................................................................................................... 16

FIGURE 3: REFERENCE DESIGN OF POWER SUPPLY ............................................................................... 17

FIGURE 4: REFERENCE CIRCUIT OF THE 6-PIN USIM CARD .................................................................... 18

FIGURE 5: REFERENCE CIRCUIT OF USB INTERFACE .............................................................................. 19

FIGURE 6: THE DCE-DTE CONNECTION OF UART INTERFACE ................................................................ 21

FIGURE 7: RS232 LEVEL MATCH CIRCUIT .................................................................................................... 21

FIGURE 8: TIMING OF PRIMARY MODE ........................................................................................................ 23

FIGURE 9: TIMING OF AUXILIARY MODE ...................................................................................................... 23

FIGURE 10: REFERENCE CIRCUIT OF PCM APPLICATION WITH AUDIO CODEC .................................... 24

FIGURE 11: RI BEHAVIOR ............................................................................................................................... 25

FIGURE 12: TIMING OF RESETTING MODULE ............................................................................................. 26

FIGURE 13: LED_WWAN# SIGNAL REFERENCE CIRCUIT DIAGRAM ........................................................ 26

FIGURE 14: DIMENSIONS OF THE RF CONNECTOR (UNIT: MM) ............................................................... 27

FIGURE 15: MECHANICALS OF UF.L-LP CONNECTORS ............................................................................. 27

FIGURE 16: MECHANICAL DIMENSIONS OF EC20 MINI PCIE (UNIT: MM) ................................................. 32

FIGURE 17: STANDARD DIMENSIONS OF MINI PCI EXPRESS (UNIT: MM) ............................................... 33

FIGURE 18: DIMENSIONS OF THE MINI PCI EXPRESS CONNECTOR (UNIT: MM) ................................... 34

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1 Introduction

This document defines EC20 Mini PCIe module and describes its hardware interfaces which are
connected with your application and air interfaces.

This document can help you to quickly understand the interface specifications, electrical and mechanical
details and related product information of the EC20 Mini PCIe module. To facilitate its application in
different fields, relevant reference design documents are also provided. Associated with application notes
and user guide of EC20 Mini PCIe module, you can use the module to design and set up mobile
applications easily.

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1.1. Safety Information

The following safety precautions must be observed during all phases of the operation, such as usage,
service or repair of any cellular terminal or mobile incorporating EC20 Mini PCIe module. Manufacturers
of the cellular terminal should send the following safety information to users and operating personnel and
to incorporate these guidelines into all manuals supplied with the product. If not so, Quectel does not take
on any liability for customer failure to comply with these precautions.

Full attention must be given to driving at all times in order to reduce the risk of an
accident. Using a mobile while driving (even with a handsfree kit) cause distraction
and can lead to an accident. You must comply with laws and regulations restricting
the use of wireless devices while driving.

Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it
switched off. The operation of wireless appliances in an aircraft is forbidden to
prevent interference with communication systems. Consult the airline staff about
the use of wireless devices on boarding the aircraft, if your device offers a Airplane
Mode which must be enabled prior to boarding an aircraft.

Switch off your wireless device when in hospitals or clinics or other health care
facilities. These requests are desinged to prevent possible interference with
sentitive medical equipment.

Cellular terminals or mobiles operate over radio frequency signal and cellular
network and cannot be guaranteed to connect in all conditions, for example no
mobile fee or an invalid SIM card. While you are in this condition and need
emergent help, please remember using emergency call. In order to make or
receive call, the cellular terminal or mobile must be switched on and in a service
area with adequate cellular signal strength.

Your cellular terminal or mobile contains a transmitter and receiver. When it is ON,
it receives and transmits radio frequency energy. RF interference can occur if it is
used close to TV set, radio, computer or other electric equipment.

In locations with potencially explosive atmospheres, obey all posted signs to turn
off wireless devices such as your phone or other cellular terminals. Areas with
potencially exposive atmospheres including fuelling areas, below decks on boats,
fuel or chemical transfer or storage facilities, areas where the air contains
chemicals or particles such as grain, dust or metal powders.

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2 Product Concept

2.1. General Description

EC20 Mini PCIe module provides data connectivity on FDD-LTE, WCDMA and GSM networks with PCI
Express Mini Card 1.2 standard interface. It supports embedded operating system such as WinCE, Linux
and Android etc., and also provides audio, high-speed data transmission and GPS/GLONASS
functionality for your applications.

EC20 Mini PCIe module can be applied in the following fields:

 PDAs and Laptop Computer
 Remote Monitor System
 Vehicle System
 Wireless POS System
 Intelligent Meter Reading System
 Wireless Router and Switch
 Other Wireless Terminal Device

This chapter generally introduces the following aspects of EC20 Mini PCIe module:

 Product Series
 Key Features
 Functional Diagram



EC20 Mini PCIe contains Telematics version and Data-Only version. Telematics version supports voice
and data, while Data-Only version only supports data.

2.2. Description of Product Series

The following table shows the product series of EC20 Mini PCIe module.

NOTE

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Table 1: Description of EC20 Mini PCIe

1.

1)

GPS/GLONASS function is optional.

2. 2) Digital audio (PCM) function is only supported in Telematics version.

2.3. Key Features

The following table describes the detailed features of EC20 Mini PCIe module.

Table 2: Key Features of EC20 Mini PCIe

Product Series

Description

EC20-E Mini PCIe

Support GSM: 850/900/1800/1900MHz
Support UMTS: B1/B5/B8
Support LTE FDD: B1/B3/B5/B7/B8/B20
Support LTE/UMTS receive diversity
Support GPS/GLONASS1)
Support digital audio2)

EC20-A Mini PCIe

Support GSM: 850/1900MHz
Support UMTS: B2/B4/B5
Support LTE FDD: B2/B4/B5/B12/B17
Support LTE/UMTS receive diversity
Support GPS/GLONASS1)
Support digital audio2)

Feature

Details

Function Interface

PCI Express Mini Card 1.2 Standard Interface

Power Supply

Supply voltage: 3.0~3.6V
Typical supply voltage: 3.3V

Transmitting Power

Class 4 (33dBm±2dB) for GSM850 and EGSM900
Class 1 (30dBm±2dB) for DCS1800 and PCS1900
Class E2 (27dBm±3dB) for GSM850 and EGSM900 8-PSK
Class E2 (26dBm±3dB) for DCS1800 and PCS1900 8-PSK
Class 3 (24dBm+1/-3dB) for UMTS B1/B2/B4/B5/B8
Class 3 (23dBm±2dB) for LTE FDD B1/B2/B3/B4/B5/B7/B8/B12/B17/B20

LTE Features

Support category3 FDD and corresponded with 3GPP R9
Support 1.4 to 20MHz RF bandwidth

NOTES

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Support 2 × 2 MIMO in DL direction
Max 100Mbps (DL), Max 50Mbps (UL)

WCDMA Features

R99 CS data: Max 64kbps (DL), Max 64kbps (UL)
R99 PS data: Max 384kbps (DL), Max 384kbps (UL)
R5 HSDPA: Max 7.2Mbps (DL)
R6 HSUPA: Max 5.76Mbps (UL)
R7 HSPA+: Max 21Mbps (DL), Max 5.76Mbps (UL)
R8 DC-HSPA+: Max 42Mbps (DL)

GSM Features

R99: CS data: 9.6k, 14.4kbps
GPRS: Support GPRS multi-slot class 12

Coding scheme: CS-1, CS-2, CS-3 and CS-4
Maximum of four Rx time slots per frame

EDGE: Support EDGE multi-slot class 12

Support GMSK and 8-PSK for different MCS (Modulation and
Coding Scheme)
Downlink coding schemes: CS 1-4, MCS 1-9
Uplink coding schemes: CS 1-4, MCS 1-9

Internet Protocol
Features

Support PPP protocols
Support the protocols PAP (Password Authentication Protocol) and CHAP
(Challenge Handshake Authentication Protocol) usually used for PPP
connections

SMS

Text and PDU mode
Point to point MO and MT
SMS cell broadcast
SMS storage: ME by default

USIM Interface

Support USIM/SIM card: 1.8V, 3.0V

UART Interface

Support two lines on UART interface
Baud rate can reach up to 230400bps, 115200bps by default
Used for AT command
Support multiplexing function*

PCM Interface

Support 8-bit A-law*, μ-law* and 16-bit linear data formats
Support long frame sync and short frame sync
Support master and slave mode, but must be the master in long frame sync

USB Interface

Compliant with USB 2.0 specification (slave only), the data transfer rate
can reach up to 480Mbps.
Used for AT command communication, data transmission, firmware
upgrade, software debug and GNSS NMEA output.
USB Driver: Support Windows XP, Windows Vista, Windows 7, Windows
8/8.1, Linux 2.6 or later, Android 2.3/4.0/4.2/4.4.

Antenna Interface

Include main LTE/UMTS/GSM antenna, LTE/UMTS diversity antenna,
GNSS antenna (passive)

GNSS Features

gpsOne Gen8A of Qualcomm (GPS and GLONASS)

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1. “*” means this function is under development.

2. “▲” means when the module works within this temperature range, RF performance might degrade.
For example, the frequency error or the phase error may increase.

2.4. Functional Diagram

The following figure shows a block diagram of EC20 Mini PCIe.

EC20

Module

PCM&I2C

Mini PCI Express

Interface

USB

USIM

W_DISABLE#
PERST#

LED_WWAN#

Main

Antenna

Interface

VCC

Main

Antenna

VBAT

GNSS

Antenna

Interface

GNSS

Antenna

Boost

Circuit

Diversity
Antenna

Interface

Diversity
Antenna

USIM Holder

(Optional)

RI

UART

DTR

Figure 1: Functional Diagram

Protocol: NMEA 0183

Rx-diversity

Support LTE/UMTS Rx-diversity

AT Commands

Compliant with 3GPP TS 27.007, 27.005 and Quectel enhanced AT
commands

Physical Characteristics

Size: 51.0mm × 30.0mm × 4.9mm
Weight: approx. 9.8g

Temperature Range

Normal operation: -30°C ~ +70°C
Restricted operation: -40°C ~ -30°C and +70°C ~ +80°C▲
Storage temperature: -45°C ~ +90°C

Firmware Upgrade

USB interface

RoHS

All hardware components are fully compliant with EU RoHS directive

NOTES

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3 Application Interface

3.1. General Description

The physical connections and signal levels of EC20 Mini PCIe comply with PCI Express Mini CEM
specifications. This chapter mainly describes the following interface definition and application of EC20
Mini PCIe:

 Power supply
 USIM interface
 USB interface
 UART interface
 PCM&I2C interface
 Control signals
 Antenna interface

3.2. EC20 Mini PCIe Interface

3.2.1. Definition of Interface

The following tables show the pin assignments of EC20 Mini PCIe on the 52-pin application.

Table 3: Definition of IO Parameters

Type

Description

IO

Bidirectional input/output

DI

Digital input

DO

Digital output

OC

Open collector

OD

Open drain

PI

Power input

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Table 4: Description of Pin

PO

Power output

Pin No.

Mini PCI Express
Standard Name

EC20 Mini PCIe
Pin Name

I/O

Description

Comment

1

WAKE#

RESERVED

—

Reserved

2

3.3Vaux

VCC_3V3

PI

3.3V DC supply

3

COEX1

RESERVED

—

Reserved

4

GND

GND

Mini Card ground

5 COEX2

RESERVED

—

Reserved

6

1.5V

NC — —

7 CLKREQ#

RESERVED

—

Reserved

8

UIM_PWR

USIM_VDD

PO

Power source for the
USIM/SIM card

9

GND

GND

Mini Card ground

10

UIM_DATA

USIM_DATA

IO

USIM/SIM data signal

11

REFCLK-

UART_RX

DI

UART receive data

Connect to
DTE’s TX

12

UIM_CLK

USIM_CLK

DO

USIM/SIM clock signal

13

REFCLK+

UART_TX

DO

UART transmit data

Connect to

DTE’s RX

14

UIM_RESET

USIM_RST

DO

USIM/SIM reset signal

15

GND

GND

Mini Card ground

16

UIM_VPP

RESERVED

—

Reserved

17

RESERVED

RI

DO

URC ring indication

18

GND

GND

Mini Card ground

19

RESERVED

RESERVED

—

Reserved

20

W_DISABLE#

W_DISABLE#

DI

Disable wireless
communications

Pull-up,
Active low

21

GND

GND

Mini Card ground

22

PERST#

PERST#

DI

Functional reset to the card

Active low

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23

PERn0

RESERVED

—

Reserved

24

3.3Vaux

RESERVED

—

Reserved

25

PERp0

RESERVED

—

Reserved

26

GND

GND

Mini Card ground

27

GND

GND

Mini Card ground

28

1.5V

NC — —

29

GND

GND

Mini Card ground

30

SMB_CLK

I2C_SCL

OD

I2C serial clock

31

PETn0

DTR

DI

Sleep mode control

32

SMB_DATA

I2C_SDA

OD

I2C serial data

33

PETp0

RESERVED

—

Reserved

34

GND

GND

Mini Card ground

35

GND

GND

Mini Card ground

36

USB_D-

USB_DM

IO

USB differential data (-)

37

GND

GND

Mini Card ground

38

USB_D+

USB_DP

IO

USB differential data (+)

39

3.3Vaux

VCC_3V3

PI

3.3V DC supply

40

GND

GND

Mini Card ground

41

3.3Vaux

VCC_3V3

PI

3.3V DC supply

42

LED_WWAN#

LED_WWAN#

OC

Active-low LED signal for
indicating the state of the
card

43

GND

GND

Mini Card ground

44

LED_WLAN#

RESERVED

—

Reserved

45

RESERVED

PCM_CLK*

IO

PCM clock signal

46

LED_WPAN#

RESERVED

—

Reserved

47

RESERVED

PCM_DOUT*

DO

PCM data output

48

1.5V

NC — —

49

RESERVED

PCM_DIN*

DI

PCM data input

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1. The typical supply voltage is 3.3V.

2. Keep all NC, reserved and unused pins unconnected.

3. Pay attention to the height of Mini PCI Express connector located on DTE, and USIM pins 8, 10, 12

and 14 cannot be used at the same time when using the optional USIM holder.

4. “*” means digital audio (PCM) function is only supported on Telematics version.

3.2.2. Pin Assignment

The following figure shows the pin assignment of EC20 Mini PCIe module. The top side contains EC20
module and antenna connectors.

PIN2

PIN52

BOT

PIN1

PIN51

TOP

Figure 2: Pin Assignment

50

GND

GND

Mini Card ground

51

RESERVED

PCM_SYNC*

IO

PCM frame sync

52

3.3Vaux

VCC_3V3

PI

3.3V DC supply

NOTES

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3.3. Power Supply

The following table shows the VCC_3V3 pins and ground pins.

Table 5: VCC_3V3 and GND Pin Definition

The typical supply voltage of EC20 Mini PCIe is 3.3V. In the 2G networks, the input peak current may
reach to 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.

VCC_3V3

C1

470uF

+

C2

100nF

C3

470uF

+

C4

33pFC510pF

R1

R2
75K

R3

43K

IN

EN

GND ADJ

OUT

MIC29302WU

LDO_IN

R4

470R

51K

D1

TVS

Figure 3: Reference Design of Power Supply

Pin No.

Pin Name

I/O

Power Domain

Description

2, 39, 41, 52

VCC_3V3

PI

3.0~3.6V

3.3V DC supply

4, 9, 15, 18, 21,
26, 27, 29, 34, 35,
37, 40, 43, 50

GND

Mini Card ground

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3.4. USIM Card Interface

The following table shows the pin definition of the USIM card interface.

Table 6: USIM Pin Definition

EC20 Mini PCIe supports 1.8V and 3.0V USIM cards. The following figure shows the reference design of
the 6-pin USIM card.

USIM_VDD

GND

USIM_RST
USIM_CLK

USIM_DATA

22R

22R
22R

100nF

USIM Holder

GND

33pF 33pF33pF

VCC
RST
CLK IO

VPP

GND

GND

33pF

15K

Module

USIM_VDD

Figure 4: Reference Circuit of the 6-Pin USIM Card

In order to enhance the reliability and availability of the USIM card in your application, please follow the
criteria below in the USIM circuit design:

 Keep layout of USIM card as close to the module as possible. Assure the length of the trace as less

than 200mm as possible.

 Keep USIM card signal away from RF and power supply alignment.
 Keep the width of ground and USIM_VDD no less than 0.5mm to maintain the same electric potential.

The decouple capacitor of USIM_VDD should be less than 1uF and must near to USIM holder.

Pin No.

Pin Name

I/O

Power Domain

Description

8

USIM_VDD

PO

1.8V/3.0V

Power source for the USIM/SIM card

10

USIM_DATA

IO

1.8V/3.0V

USIM/SIM data signal

12

USIM_CLK

DO

1.8V/3.0V

USIM/SIM clock signal

14

USIM_RST

DO

1.8V/3.0V

USIM/SIM reset signal

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 To avoid cross-talk between USIM_DATA and USIM_CLK, keep them away from each other and

shield them with surrounding ground.

 In order to offer good ESD protection, it is recommended to add TVS. The 22R resistors should be

added in series between the module and USIM card so as to suppress the EMI spurious transmission
and enhance the ESD protection. The 33pF capacitors are used for filtering interference of
GSM850/EGSM900. Please note that the USIM peripheral circuit should be close to the USIM card
holder.

 The pull-up resistor on USIM_DATA line can improve anti-jamming capability when long layout trace

and sensitive occasion are applied, and should be placed close to the holder.

3.5. USB Interface

The following table shows the pin definition of USB interface.

Table 7: USB Pin Definition

EC20 Mini PCIe is compliant with USB 2.0 specification. It can only be used as a slave device. Meanwhile,
it supports high speed (480Mbps) and full speed (12Mbps) mode. The USB interface is used for AT
command, data transmission, GNSS NMEA output, software debug and firmware upgrade. The following
figure shows the reference circuit of USB interface.

Module

GND

MCU

Differential layout

USB_DM

GND

NM_2pF

VCC_MCU

VCC

USB_DP

USB_DM

USB_DP

Figure 5: Reference Circuit of USB Interface

Pin No.

Pin Name

I/O

Description

Comment

36

USB_DM

IO

USB differential data (-)

Require differential impedance of 90Ω

38

USB_DP

IO

USB differential data (+)

Require differential impedance of 90Ω

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In order to ensure the USB interface design corresponding with the USB 2.0 specification, please comply
with the following principles:

 It is important to route the USB signal traces as differential pairs with total grounding. The impedance

of USB differential trace is 90ohm.

 Do not route signal traces under crystals, oscillators, magnetic devices and RF signal traces. It is

important to route the USB differential traces in inner-layer with ground shielding, and not only upper
and lower layer but also right and left side should be shielded.

 If you use the USB connector, you should keep the ESD components as close to the USB connector

as possible. Pay attention to the influence of junction capacitance of ESD component on USB data
lines. Typically, the capacitance value should be less than 2pF.

There are three preconditions when enabling EC20 Mini PCIe to enter into the sleep mode:

1. Execute AT command AT+QSCLK=1 to enable the sleep mode. Refer to document [2].

2. DTR pin should be kept in high level (pull-up internally).

3. USB interface on Mini PCIe must be connected with your USB interface and please guarantee

USB devices are in the suspended state.

3.6. UART Interface

The following table shows the pin definition of the UART interface.

Table 8: Pin Definition of the UART Interface

The UART interface supports 9600, 19200, 38400, 57600, 115200 and 230400bps baud rate. The default
is 115200bps. This interface can be used for AT communication.

EC20 Mini PCIe is designed as the DCE, and the DCE-DTE connection of UART interface is shown as
below.

Pin No.

EC20 Mini PCIe Pin Name

I/O

Power Domain

Description

11

UART_RX

DI

3.3V

UART receive data

13

UART_TX

DO

3.3V

UART transmit data

NOTES

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UART_RX
UART_TX

DTR

RI

TXD

RXD

DTR

RI

EC20 Mini PCIe Application

DCE DTE

GND GND

Figure 6: The DCE-DTE Connection of UART Interface

The following figure is an example of connection between EC20 Mini PCIe and PC. Since the UART
interface does not support the RS-232 level, A RS-232 level translator IC must be inserted between
module and PC. A RS-232 level shifter SN65C3238 provided by Texas Instruments is recommended.
The following figure shows the reference design of RS232 level match circuit.

DTR

UART_RX

RI

UART_TX

EC20 Mini PCIe

GND

3.3V

DIN1

ROUT3

ROUT2

ROUT1

DIN4

DIN3

DIN2

DIN5
R1OUTB

FORCEON

/FORCEOFF

/INVALID

3.3V

DOUT1
DOUT2
DOUT3
DOUT4
DOUT5

RIN3

RIN2

RIN1

VCC GND

SN65C3238 DB9(PC)

DCD

RTS

DTR

TXD

RI

CTS

RXD

DSR

GND

1

2

3
4

5

6

7

8
9

Figure 7: RS232 Level Match Circuit

AT command AT+IPR is used to set the baud rate of the UART. Please refer to document [2] for details.

NOTE

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3.7. PCM and I2C Interface

The following table shows the pin definition of PCM interface that can be applied in audio codec design.

Table 9: PCM and I2C Pin Definition

EC20 Mini PCIe provides one PCM digital interface, which supports 8-bit A-law and μ-law, 16-bit linear
data formats and the following modes:

 Primary mode (short sync, works as either master or slave)
 Auxiliary mode (long sync, works as master only)

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 128kHz,
256kHz, 512kHz, 1024kHz, 2048kHz and 4096kHz. The following figure shows timing relationship in
primary mode with 8kHz PCM_SYNC and 2048kHz PCM_CLK.

Pin No.

Pin Name

I/O

Power Domain

Description

45

PCM_CLK

IO

1.8V

PCM clock signal

47

PCM_DOUT

DO

1.8V

PCM data output

49

PCM_DIN

DI

1.8V

PCM data input

51

PCM_SYNC

IO

1.8V

PCM frame sync

30

I2C_SCL

OD

1.8V

I2C serial clock, require external
pull-up to 1.8V

32

I2C_SDA

OD

1.8V

I2C serial data, require external
pull-up to 1.8V

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PCM_CLK

PCM_SYNC

PCM_DOUT

MSB

LSB

MSB

MSB

LSB

MSB

PCM_DIN

125us

1 2 256255

Figure 8: Timing of 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 9: Timing of Auxiliary Mode

Clock and mode can be configured by AT command, and the default configuration is master mode using
short sync data format with 2048kHz PCM_CLK and 8kHz PCM_SYNC.

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The following figure shows the reference design of PCM interface with external codec IC (such as
ALC5616).

PCM_DIN

PCM_DOUT

PCM_SYNC

PCM_CLK

I2C_SCL

I2C_SDA

Codec

Module

1.8V

4.7K

4.7K

BCLK
FS
DACIN
ADCOUT

SCLK
SDIN

BIAS

MIC_BIAS

MIC+

MIC-

SPKOUT+

SPKOUT-

Figure 10: Reference Circuit of PCM Application with Audio Codec

3.8. Control Signals

The following table shows the pin definition of control signals.

Table 10: Control Signal Pin Definition

Pin No.

Pin Name

I/O

Power Domain

Description

17

RI

DO

3.3V

URC ring indication, can be used to
wake up the host

31

DTR

DI

3.3V

Sleep mode control

20

W_DISABLE#

DI

3.3V

Disable wireless communications
Pull-up by default. Active low

22

PERST#

DI

3.3V

Functional reset to the card
Active low

42

LED_WWAN#

OC

—

Active-low LED signal for indicating
the state of the Module

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3.8.1. RI Signal

The RI signal can be used to wake up the host. When URC returns, there will be the following behavior on
the RI pin.

URC return

120 ms

High

Low

Figure 11: RI Behavior

3.8.2. DTR Signal

The DTR signal supports sleep control function, drive it to low level will wake up the module. AT command

AT+QCFG="pwrsavedtr" is used to disable the sleep control function.

3.8.3. W_DISABLE# Signal

EC20 Mini PCIe provides W_DISABLE# signal to disable wireless communications through hardware
operation. The following table shows the radio operational states of module. Please refer to document [2]
for related AT commands.

Table 11: Radio Operational States

W_DISABLE#

AT Commands

Radio Operation

High Level

AT+CFUN=1

Enabled

High Level

AT+CFUN=0
AT+CFUN=4

Disabled

Low Level

AT+CFUN=0
AT+CFUN=1
AT+CFUN=4

Disabled

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3.8.4. PERST# Signal

The PERST# signal can be used to force a hardware reset on the card. You can reset the module by
driving the PERST# to a low level voltage of more than 150ms and then release it. The reset scenario is
illustrated in the following figure.

VIL ≤ 0.5V

VIH ≥ 2.3V

VCC_3V3

150ms

RESETTING

Module
Status

RUNNING

PERST#

RUNNING

≥ 19s

Figure 12: Timing of Resetting Module

3.8.5. LED_WWAN# Signal

The LED_WWAN# signal of EC20 Mini PCIe is used to indicate the network status of the module, which
can absorb the current up to 40mA. According to the following circuit, in order to reduce the current of the
LED, a resistor must be placed in series with the LED. The LED is emitting light when the LED_WWAN#
output signal is active low.

LED_WWAN#

VCC

R

Figure 13: LED_WWAN# Signal Reference Circuit Diagram

The following table shows the indications of network status of the LED_WWAN# signal.

Table 12: Indication of Network Status

LED_WWAN#

Description

Low Level (Light on)

Registered network

High-impedance (Light off)

 No network coverage or not registered
 W_DISABLE# signal is in low level. (Disable the RF)
 AT+CFUN=0, AT+CFUN=4

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3.9. Antenna Interface

EC20 Mini PCIe antenna interfaces include a main LTE/UMTS/GSM antenna interface, a LTE/UMTS
Rx-diversity antenna interface and a GNSS antenna interface. All of these connectors are ECT818000117.
The following figure shows the overall sizes of RF connector.

Figure 14: Dimensions of the RF Connector (Unit: mm)

You can use U.FL-LP serial connector listed in the following figure to match the ECT818000117. For more
details, please visit http://www.hirose.com.

Figure 15: Mechanicals of UF.L-LP Connectors

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4 Electrical and Radio Characteristics

4.1. General Description

This chapter mainly describes the following electrical and radio characteristics of EC20 Mini PCIe:

 Power supply requirements
 IO requirements
 Current consumption
 RF characteristics
 GNSS receiver
 ESD characteristics

4.2. Power Supply Requirements

The input voltage of EC20 Mini PCIe is 3.3V±9%, as specified by PCI Express Mini CEM Specifications

1.2. The following table shows the power supply requirements of EC20 Mini PCIe.

Table 13: Power Supply Requirements

Parameter

Description

Min.

Typ.

Max.

Unit

VCC_3V3

Power Supply

3.0

3.3

3.6

V

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4.3. IO Requirements

The following table shows the IO requirements of EC20 Mini PCIe.

Table 14: IO Requirements

1. The PCM and I2C interface belong to 1.8V power domain, and other IO interfaces belong to 3.3V

power domain.

2. The maximum value of V

IL

for PERST# signal and W_DISABLE# signal is 0.5V.

4.4. RF Characteristics

The following tables show output power and receiving sensitivity of conducted RF of EC20 Mini PCIe
module.

Table 15: Output Power of Conducted RF

Parameter

Description

Min.

Max.

Unit

VIH

Input High Voltage

0.7*VDDIO

VDDIO+0.3

V

VIL

Input Low Voltage

-0.3

0.3*VDDIO

V

VOH

Output High Voltage

VDDIO-0.5

VDDIO

V

VOL

Output Low Voltage

0

0.4

V

Frequency

Max.

Min.

GSM850/EGSM900

33dBm±2dB

5dBm±5dB

DCS1800/PCS1900

30dBm±2dB

0dBm±5dB

GSM850/EGSM900(8-PSK)

27dBm±3dB

5dBm±5dB

DCS1800/PCS1900(8-PSK)

26dBm±3dB

0dBm±5dB

UMTS B1/B2/B4/B5/B8

24dBm+1/-3dB

<-50dBm

LTE B1/B2/B3/B4/B5/B7/B8/B12/B17/B20

23dBm±2dB

<-44dBm

NOTES

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Table 16: Conducted RF Receiving Sensitivity

Frequency

Receive Sensitivity (Typ.)

GSM850

-111dBm

EGSM900

-110dBm

DCS1800

-109dBm

PCS1900

-109dBm

UMTS B1

-110dBm

UMTS B5

-112dBm

UMTS B8

-111dBm

LTE FDD B1 (20M)

-97dBm

LTE FDD B3 (20M)

-96dBm

LTE FDD B5 (10M)

-99dBm

LTE FDD B7 (20M)

-97dBm

LTE FDD B8 (10M)

-98dBm

LTE FDD B20 (20M)

-96dBm

4.5. GNSS Receiver

EC20 Mini PCIe integrates a GNSS receiver that supports gpsOne Gen8A of Qualcomm (GPS and
GLONASS), and could be used in Qualcomm gpsOneXTRA technology (one kind of A-GNSS). This
technology will download XTRA file from the internet server to enhance the TTFF. XTRA file contains
predicted GPS and GLONASS satellites coordinates and clock biases valid for up to 7 days. It is best if
XTRA file is downloaded every 1-2 days. Additionally, EC20 Mini PCIe can support standard
NMEA-0183 protocol and output NMEA messages with 1Hz via USB NMEA interface.

EC20 Mini PCIe GNSS engine is switched off by default. You must switch on it by AT command. Please
refer to document [3] for more details about GNSS engine technology and configurations. In addition, it
should use passive antenna.

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4.6. ESD Characteristics

The following table shows characteristics of EC20 Mini PCIe ESD.

Table 17: ESD Characteristics

Part

Contact Discharge

Air Discharge

Unit

Power Supply and GND

+/-5

+/-10

kV

Antenna Interface

+/-4

+/-8

kV

USB Interface

+/-4

+/-8

kV

USIM Interface

+/-4

+/-8

kV

Others

+/-0.5

+/-1

kV

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5 Mechanical Dimensions

5.1. General Description

This chapter mainly describes the following dimensions of EC20 Mini PCIe:

 Mechanical Dimensions of EC20 Mini PCIe
 Standard Dimensions of Mini PCI Express
 Packaging

5.2. Mechanical Dimensions of EC20 Mini PCIe

Figure 16: Mechanical Dimensions of EC20 Mini PCIe (Unit: mm)

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5.3. Standard Dimensions of Mini PCI Express

The following figure shows the standard Dimensions of Mini PCI Express. Please refer to document [1]
for detailed A and B.

Figure 17: Standard Dimensions of Mini PCI Express (Unit: mm)

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EC20 Mini PCIe adopts a standard Mini PCI Express connector which compiles with the directives and
standards listed in the document [1]. The following figure takes the Molex 679100002 as an example.

Figure 18: Dimensions of the Mini PCI Express Connector (Unit: mm)

5.4. Packaging

The EC20 Mini PCIe is packaged in tray. Each tray contains 10pcs of modules. The smallest package of
EC20 Mini PCIe contains 100pcs.

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6 Appendix Reference

Table 18: Related Documents

Table 19: Terms and Abbreviations

SN

Document Name

Remark

[1]

PCI Express Mini Card Electromechanical
Specification Revision 1.2

Mini PCI Express Specification

[2]

Quectel_EC20_AT_Commands_Manual

EC20 AT Commands Manual

[3]

Quectel_EC20_GNSS_AT_Commands_Manual

EC20 GNSS AT Commands Manual

Abbreviation

Description

bps

Bits Per Second

CS

Coding Scheme

CS

Circuit Switched

DC-HSPA+

Dual-carrier High Speed Packet Access

DL

Down Link

ESD

Electrostatic Discharge

FDD

Frequency Division Duplexing

GLONASS

GLObalnaya Navigatsionnaya Sputnikovaya Sistema, the Russian Global
Navigation Satellite System

GMSK

Gaussian Minimum Shift Keying

GNSS

Global Navigation Satellite System

GPS

Global Positioning System

GSM

Global System for Mobile Communications

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HSPA

High Speed Packet Access

HSDPA

High Speed Downlink Packet Access

HSUPA

High Speed Uplink Packet Access

kbps

Kilo Bits Per Second

LED

Light Emitting Diode

LTE

Long-Term Evolution

Mbps

Million Bits Per Second

ME

Mobile Equipment (Module)

MIMO

Multiple-Input Multiple-Output

MMS

Multimedia Messaging Service

MO

Mobile Originated

MT

Mobile Terminated

PCM

Pulse Code Modulation

PDU

Protocol Data Unit

PPP

Point-to-Point Protocol

RF

Radio Frequency

Rx

Receive

USIM

Universal Subscriber Identification Module

SMS

Short Message Service

TTFF

Time To First Fix

UART

Universal Asynchronous Receiver & Transmitter

UL

Up Link

UMTS

Universal Mobile Telecommunications System

URC

Unsolicited Result Code

WCDMA

Wideband Code Division Multiple Access

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