Sierra Wireless AR7550 Operators Guide

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Product Technical Specification

Important Notice

Due to the nature of wireless communications, transmission and reception of data can never be
guaranteed. Data may be delayed, corrupted (i.e., have errors) or be totally lost. Although significant
delays or losses of data are rare when wireless devices such as the Sierra Wireless modem are used
in a normal manner with a well-constructed network, the Sierra Wireless modem should not be used
in situations where failure to transmit or receive data could result in damage of any kind to the user or
any other party, including but not limited to personal injury, death, or loss of property. Sierra Wireless
accepts no responsibility for damages of any kind resulting from delays or errors in data transmitted or
received using the Sierra Wireless modem, or for failure of the Sierra Wireless modem to transmit or
receive such data.

Safety and Hazards

Do not operate the Sierra Wireless modem in areas where cellular modems are not advised without
proper device certifications. These areas include environments where cellular radio can interfere
such as explosive atmospheres, medical equipment, or any other equipment which may be
susceptible to any form of radio interference. The Sierra Wireless modem can transmit signals that
could interfere with this equipment. Do not operate the Sierra Wireless modem in any aircraft, whether

the aircraft is on the ground or in flight. In aircraft, the Sierra Wireless modem MUST BE POWERED
OFF. When operating, the Sierra Wireless modem can transmit signals that could interfere with

various onboard systems.

Note: Some airlines may permit the use of cellular phones while the aircraft is on the ground and the door

is open. Sierra Wireless modems may be used at this time.

The driver or operator of any vehicle should not operate the Sierra Wireless modem while in control of
a vehicle. Doing so will detract from the driver or operator’s control and operation of that vehicle. In
some states and provinces, operating such communications devices while in control of a vehicle is an
offence.

Limitations of Liability

This manual is provided “as is”. Sierra Wireless makes no warranties of any kind, either expressed or
implied, including any implied warranties of merchantability, fitness for a particular purpose, or
noninfringement. The recipient of the manual shall endorse all risks arising from its use.

The information in this manual is subject to change without notice and does not represent a
commitment on the part of Sierra Wireless. SIERRA WIRELESS AND ITS AFFILIATES
SPECIFICALLY DISCLAIM LIABILITY FOR ANY AND ALL DIRECT, INDIRECT, SPECIAL,
GENERAL, INCIDENTAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES INCLUDING,
BUT NOT LIMITED TO, LOSS OF PROFITS OR REVENUE OR ANTICIPATED PROFITS OR
REVENUE ARISING OUT OF THE USE OR INABILITY TO USE ANY SIERRA WIRELESS
PRODUCT, EVEN IF SIERRA WIRELESS AND/OR ITS AFFILIATES HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES OR THEY ARE FORESEEABLE OR FOR CLAIMS BY ANY
THIRD PARTY.

Notwithstanding the foregoing, in no event shall Sierra Wireless and/or its affiliates aggregate liability
arising under or in connection with the Sierra Wireless product, regardless of the number of events,
occurrences, or claims giving rise to liability, be in excess of the price paid by the purchaser for the
Sierra Wireless product.

Customer understands that Sierra Wireless is not providing cellular or GPS (including A-GPS)
services. These services are provided by a third party and should be purchased directly by the
Customer.

41124764188 Rev 0.41 March 20, 2013 2

Product Technical Specification

SPECIFIC DISCLAIMERS OF LIABILITY: CUSTOMER RECOGNIZES AND ACKNOWLEDGES
SIERRA WIRELESS IS NOT RESPONSIBLE FOR AND SHALL NOT BE HELD LIABLE FOR ANY
DEFECT OR DEFICIENCY OF ANY KIND OF CELLULAR OR GPS (INCLUDING A-GPS)
SERVICES.

Patents

This product may contain technology developed by or for Sierra Wireless Inc.

This product includes technology licensed from QUALCOMM

This product is manufactured or sold by Sierra Wireless Inc. or its affiliates under one or more patents
licensed from InterDigital Group and MMP Portfolio Licensing.

®

.

Copyright

© 2013 Sierra Wireless. All rights reserved.

Trademarks

AirCard

AirVantage™, Watcher™ and the Sierra Wireless logo are trademarks of Sierra Wireless.

filed or registered trademarks of Sierra Wireless S.A. in France and/or in other countries.

Windows

Macintosh and Mac OS are registered trademarks of Apple Inc., registered in the U.S. and other
countries.

QUALCOMM

Other trademarks are the property of the respective owners.

®

is a registered trademark of Sierra Wireless. Sierra Wireless™, AirPrime™, AirLink™,

®

, inSIM®, WAVECOM®, WISMO®, Wireless Microprocessor®, Wireless CPU®, Open AT® are

,

®

and Windows Vista® are registered trademarks of Microsoft Corporation.

®

is a registered trademark of QUALCOMM Incorporated. Used under license.

Contact Information

Phone: [phone]

Sales Desk:

Post:

Technical Support:

RMA Support:

Web:

Hours: 8:00 AM to 5:00 PM Pacific Time

E-mail:

Sierra Wireless
13811 Wireless Way
Richmond, BC
Canada V6V 3A4

[e-mail]

[e-mail]

Fax: [phone]

www.sierrawireless.com

[e-mail]

Consult our website for up-to-date product descriptions, documentation, application notes, firmware
upgrades, troubleshooting tips, and press releases: www.sierrawireless.com

41124764188 Rev 0.41 March 20, 2013 3

Product Technical Specification

Document History

Version Date Updates

Creation based on document 4112476: AirePrime – AR755x Series – Product

0.1 March 29, 2013

Technical Specification – Rev0.4.

41124764188 Rev 0.41 March 20, 2013 4

Contents

1. INTRODUCTION ................................................................................................ 11

1.1. General Features ............................................................................................................ 11

2. FUNCTIONAL SPECIFICATIONS ...................................................................... 12

2.1. Modes of Operation ......................................................................................................... 12

2.2. Communications Functions ............................................................................................. 12

2.3. Block Diagrams ............................................................................................................... 13

3. HARDWARE SPECIFICATIONS ........................................................................ 14

3.1. Environmental Specifications .......................................................................................... 14

3.2. Electrical Specifications ................................................................................................... 14

3.2.1. Absolute Maximum and ESD Ratings ...................................................................... 14

3.3. Mechanical Specifications ............................................................................................... 15

3.3.1. Physical Dimensions and Connection Interface ....................................................... 15

3.3.2. Mechanical Drawing ................................................................................................. 16

3.3.3. Footprint ................................................................................................................... 17

3.3.4. Thermal Consideration ............................................................................................. 18

4. RF SPECIFICATION .......................................................................................... 19

4.1. LTE RF Interface ............................................................................................................. 19

4.1.1. LTE Max TX Output Power ...................................................................................... 19

4.1.2. LTE RX Sensitivity ................................................................................................... 20

4.2. CDMA RF Interface ......................................................................................................... 20

4.2.1. CDMA Max TX Output Power .................................................................................. 20

4.2.2. CDMA RX Sensitivity ............................................................................................... 21

4.3. WCDMA RF Interface ...................................................................................................... 21

4.3.1. WCDMA Max TX Output Power ............................................................................... 21

4.3.2. WCDMA RX Sensitivity ............................................................................................ 21

4.4. WWAN Antenna Interface ............................................................................................... 22

4.4.1. WWAN Antenna Recommendations ........................................................................ 22

4.5. Primary Antenna Diagnostics .......................................................................................... 23

4.6. RX2 Antenna Diagnostics ............................................................................................... 23

5. GNSS SPECIFICATION ..................................................................................... 25

5.1. GNSS .............................................................................................................................. 25

5.2. GNSS Antenna Interface ................................................................................................. 25

5.2.1. GNSS Antenna Recommendations ......................................................................... 26

5.3. GNSS Antenna Diagnostics ............................................................................................ 26

5.4. Current Consumption ...................................................................................................... 29

5.5. Digital IO Characteristics ................................................................................................. 29

5.6. Internal Device Frequencies ............................................................................................ 30

4112476 Rev 0.4 March 20, 2013 5

Product Technical Specification

6. BASEBAND SPECIFICATION ........................................................................... 32

6.1. Power Supply .................................................................................................................. 32

6.1.1. Under-Voltage Lockout (UVLO) ............................................................................... 32

6.2. VCOIN ............................................................................................................................. 33

6.3. ON/OFF Control .............................................................................................................. 34

6.3.1. ON/OFF Timing ........................................................................................................ 34

6.3.3. Software-Initiated Power Down ................................................................................ 36

6.3.4. Deep Sleep............................................................................................................... 36

6.3.4.1. Sequence to Enter Deep Sleep Mode ........................................................................... 37

6.4. USB ................................................................................................................................. 37

6.5. UART ............................................................................................................................... 38

6.6. Ring Indicator .................................................................................................................. 38

6.7. UIM Interface ................................................................................................................... 39

6.7.1. Internal UIM .............................................................................................................. 39

6.8. General Purpose IO ........................................................................................................ 40

6.8.1. AT Port Switch ......................................................................................................... 40

6.9. Secure Digital IO ............................................................................................................. 40

6.10. I2C ................................................................................................................................... 41

6.11. Voltage Reference ........................................................................................................... 41

6.12. RESET ............................................................................................................................. 41

6.13. ADC ................................................................................................................................. 42

6.14. LED .................................................................................................................................. 43

6.15. Audio ............................................................................................................................... 43

6.15.1. Analog Audio ............................................................................................................ 43

6.15.2. Digital Audio ............................................................................................................. 44

6.15.2.1. PCM ............................................................................................................................ 44

6.15.2.2. I2S .............................................................................................................................. 47

6.16. SPI Bus ............................................................................................................................ 49

6.16.1. Characteristics ......................................................................................................... 49

6.16.2. SPI Configuration ..................................................................................................... 49

6.16.3. SPI Waveforms ........................................................................................................ 49

6.16.4. SPI Pin Description .................................................................................................. 50

6.16.5. Application ................................................................................................................ 50

6.17. HSIC Bus ......................................................................................................................... 51

6.17.1. HSIC Pin Description ............................................................................................... 51

6.17.2. HSIC Waveforms ..................................................................................................... 51

6.17.3. Application ................................................................................................................ 52

6.18. Temperature Monitoring .................................................................................................. 53

7. ROUTING CONSTRAINTS AND RECOMMENDATIONS ................................. 54

7.1. RF Routing Recommendations ....................................................................................... 54

7.2. Power and Ground Recommendations ........................................................................... 56

7.3. Antenna Recommendations ............................................................................................ 56

7.4. Interface Circuit Recommendations ................................................................................ 57

41124764188 Rev 0.41 March 20, 2013 6

Product Technical Specification

8. REGULATORY INFORMATION ......................................................................... 58

8.1. Important Notice .............................................................................................................. 58

8.2. Important Compliance Information for USA OEM Integrators ......................................... 58

9. REFERENCES ................................................................................................... 60

10.ABBREVIATIONS .............................................................................................. 61 

41124764188 Rev 0.41 March 20, 2013 7

List of Figures

Figure 1. AirPrime AR7550 Block Diagram .................................................................................... 13

Figure 2. AR55x Assembly Drawing ............................................................................................... 16

Figure 3. AirPrime AR7550 Mechanical Dimensions Drawing ....................................................... 16

Figure 4. AirPrime AR7550 Footprint ............................................................................................. 17

Figure 5. AirPrime AR7550 Recommended Application Land Pattern ........................................... 17

Figure 6. AirPrime AR7550 Heatsink Contact Area ....................................................................... 18

Figure 7. VGNSS_ANT vs. ADC Readings Relationship ............................................................... 28

Figure 8. GNSS Power Supply and Antenna Diagnostics Block Diagram ..................................... 28

Figure 9. Under-Voltage Lockout (UVLO) Diagram ........................................................................ 32

Figure 10. Recommended ON/OFF Control ..................................................................................... 34

Figure 11. Alternate ON/OFF Control ............................................................................................... 35

Figure 12. Power Mode Diagram ...................................................................................................... 36

Figure 13. Recommended UIM Holder Implementation ................................................................... 39

Figure 14. Illustration of Reset Timing When RESIN_N < Trdel ...................................................... 42

Figure 15. Illustration of Reset Timing When RESIN_N Held Low > Trdet+Trdel ............................ 42

Figure 16. LED Reference Circuit ..................................................................................................... 43

Figure 17. Audio Block Diagram ....................................................................................................... 43

Figure 18. PCM_FS Timing Diagram (2048 kHz Clock) ................................................................... 45

Figure 19. PCM Codec to AR Device Timing Diagram (Primary PCM) ........................................... 46

Figure 20. AR Device to PCM Codec Timing Diagram (Primary PCM) ........................................... 46

Figure 21. PCM_FS Timing Diagram (128 kHz Clock) ..................................................................... 47

Figure 22. PCM Codec to AR Device Timing Diagram (Auxiliary PCM) .......................................... 47

Figure 23. AR Device to PCM Codec Timing Diagram (Auxiliary PCM) .......................................... 47

Figure 24. I2S Signals Timing Diagram ............................................................................................ 48

Figure 25. 4-Wire Configuration SPI Transfer .................................................................................. 49

Figure 26. Example of 4-wire SPI Bus Application ........................................................................... 50

Figure 27. HSIC Signal Sample Waveforms .................................................................................... 51

Figure 28. Example of HSIC Bus Application ................................................................................... 52

Figure 29. Temperature Monitoring State Machine .......................................................................... 53

Figure 30. AppCAD Screenshot for Microstrip Design Power Mode Diagram ................................. 54

Figure 31. RF Routing Examples ..................................................................................................... 55

Figure 32. Coplanar Clearance Example ......................................................................................... 55

Figure 33. Antenna Microstrip Routing Example .............................................................................. 56

Figure 34. AirPrime AR7550 Input Reference Circuit ....................................................................... 57

Figure 35. AirPrime AR7550 Output Reference Circuit .................................................................... 57

4112476 Rev 0.4 March 20, 2013 8

List of Tables

Table 1. AirPrime AR7550 Embedded Modules ........................................................................... 11

Table 2. AirPrime AR7550 Modes of Operation ............................................................................ 12

Table 3. Communications Functions ............................................................................................. 12

Table 4. AirPrime AR7550 Environmental Specifications ............................................................. 14

Table 5. AirPrime AR7550 Absolute Maximum Ratings ................................................................ 14

Table 6. AirPrime AR7550 Embedded Module Dimensions ......................................................... 15

Table 7. AirPrime AR7550 Maximum LTE Transmitter Output Power .......................................... 19

Table 8. AirPrime AR7550 Minimum LTE Receiver Sensitivity ..................................................... 20

Table 9. AirPrime AR7550 Maximum CDMA Transmitter Output Power ...................................... 21

Table 10. AirPrime AR7550 Minimum CDMA Receiver Sensitivity ................................................. 21

Table 11. AirPrime AR7550 Maximum WCDMA Transmitter Output Power .................................. 21

Table 12. AirPrime AR7550 Minimum WCDMA Receiver Sensitivity ............................................. 21

Table 13. AirPrime AR7550 WWAN Antenna Characteristics ........................................................ 22

Table 14. WWAN Antenna Interface Pads ...................................................................................... 22

Table 15. AirPrime AR7550 WWAN Antenna Recommendations ................................................. 22

Table 16. Primary Antenna ADC Characteristics ............................................................................ 23

Table 17. Primary Antenna Diagnostics Ranges ............................................................................ 23

Table 18. RX2 Antenna ADC Characteristics.................................................................................. 23

Table 19. RX2 Antenna Diagnostics Ranges .................................................................................. 24

Table 20. GNSS Characteristics ..................................................................................................... 25

Table 21. GNSS Antenna Interface Characteristics ........................................................................ 25

Table 22. GNSS Antenna Interface Pads ........................................................................................ 26

Table 23. GNSS Recommended Antenna Characteristics ............................................................. 26

Table 24. GNSS Antenna Diagnostics Ranges ............................................................................... 26

Table 25. VGNSS_ANT Current Draw ............................................................................................ 27

Table 26. AirPrime AR7550 Current Consumption Values ............................................................. 29

Table 27. Digital IO Characteristics ................................................................................................. 29

Table 28. Internal Device Frequencies ............................................................................................ 30

Table 29. Power Supply Requirements ........................................................................................... 32

Table 30. Power Supply Pads ......................................................................................................... 32

Table 31. UVLO Thresholds ............................................................................................................ 33

Table 32. VCOIN Pad ...................................................................................................................... 33

Table 33. VCOIN Interface Specification ......................................................................................... 33

Table 34. VCOIN Charging Specifications ...................................................................................... 33

Table 35. ON/OFF Control Pads ..................................................................................................... 34

Table 36. ON/OFF Internal Pull-Up ................................................................................................. 34

Table 37. Power-ON Sequence Symbol Definitions ....................................................................... 35

4112476 Rev 0.4 March 20, 2013 9

Product Technical Specification

Table 38. Period of Wake Intervals ................................................................................................. 36

Table 39. Deep Sleep Function Availability ..................................................................................... 36

Table 40. USB Pad Details .............................................................................................................. 37

Table 41. USB Characteristics ........................................................................................................ 38

Table 42. UART Pads ...................................................................................................................... 38

Table 43. Ring Indicator Pad ........................................................................................................... 38

Table 44. UIM Pads ......................................................................................................................... 39

Table 45. GPIO Interface Pads ....................................................................................................... 40

Table 46. AT Port Switch States ..................................................................................................... 40

Table 47. SDIO Interface Pads ....................................................................................................... 40

Table 48. I2C Interface Pads ........................................................................................................... 41

Table 49. Voltage Reference Pad ................................................................................................... 41

Table 50. Voltage Reference Characteristics .................................................................................. 41

Table 51. Reset Interface Pads ....................................................................................................... 41

Table 52. Reset Timing ................................................................................................................... 42

Table 53. ADC Interface Pads ......................................................................................................... 42

Table 54. ADC Interface Characteristics ......................................................................................... 43

Table 55. LED Interface Pad ........................................................................................................... 43

Table 56. Analog Audio Interface Pads ........................................................................................... 43

Table 57. Analog Audio Interface Characteristics ........................................................................... 44

Table 58. Digital Audio Interface Pads ............................................................................................ 44

Table 59. PCM Interface Configurations ......................................................................................... 44

Table 60. Primary PCM Timing ....................................................................................................... 45

Table 61. Auxiliary PCM Timing ...................................................................................................... 46

Table 62. SPI Configuration ............................................................................................................ 49

Table 63. SPI Master Timing Characteristics .................................................................................. 50

Table 64. SPI Pin Description ......................................................................................................... 50

Table 65. HSIC Pin Description ....................................................................................................... 51

Table 66. Temperature Monitoring States ....................................................................................... 53

Table 67. Reference Specifications ................................................................................................. 60

Table 68. Abbreviations ................................................................................................................... 61

41124764188 Rev 0.41 March 20, 2013 10

1. Introduction

1.1. General Features

The AirPrime AR7550 embedded modules are designed for the automotive industry. They support
LTE, CDMA, WCDMA air interface standards and shares hardware and firmware interfaces with the
AirPrime AR5550 and AR855x. They also have Global Navigation Satellite System (GNSS)
capabilities including GPS and GLONASS.

The AirPrime AR7550 embedded modules are based on the Qualcomm MDM9615 wireless chipset
and support the following bands.

Table 1. AirPrime AR7550 Embedded Modules

Product Description Band Support

LTE: B4, B7*, B13

AirPrime
AR7550

LTE/CDMA2000/ /WCDMA embedded module

CDMA: BC0, BC1
WCDMA: B2, B5

* LTE B7 for AirPrime AR7550 is optional.

4112476 Rev 0.4 March 20, 2013 11

2. Functional Specifications

This chapter highlights the features of the AirPrime AR7550 series of embedded modules.

2.1. Modes of Operation

The AirPrime AR7550 supports 2G/3G/4G operations and also supports GNSS operation. For
complete details, refer to the table below.

Table 2. AirPrime AR7550 Modes of Operation

Frequency (MHz)

Mode Band

Downlink (DL) UE Receive Uplink (UL) UE Transmit

Band 4 2110 MHz to 2155 MHz 1710 MHz to 1755 MHz

LTE

CDMA2000 –
1xRTT & 1xEVDO

Band 7 2620MHz to 2690 MHz 2500 MHz to 2570 MHz

Band 13 746 MHz to 756 MHz 777 MHz to 787 MHz

Band Class 0 869 MHz to 894 MHz 824 MHz to 849 MHz

Band Class 1 1930 MHz to 1990 MHz 1850 MHz to 1910 MHz

WCDMA/HSPA

GNSS

Note: Supported bands vary depending on product. Refer to Table 1 AirPrime AR7550 Embedded

II (1900/PCS) 1930 MHz to 1990 MHz 1850 MHz to 1910 MHz

V (850/CELL) 869 MHz to 894 MHz 824 MHz to 849 MHz

GPS L1 1574.42 – 1576.42 ---

GLONASS L1 FDMA 1597.5 – 1605.8 ---

Modules for the list of bands supported by each module variant.

2.2. Communications Functions

The AirPrime AR7550 provides the following communications functions via the LTE, CDMAand UMTS
networks.

Table 3. Communications Functions

Communications Function LTE CDMA WCDMA GSM/GPRS/EDGE

Voice

Packet Data

Short Message Service (SMS)

OTA

DTMF

Circuit Switched EVRC, EVRC-B AMR, AMR-WB FR, EFR, HR

VoLTE

OTAPA

OTASP



   

  





  

4112476 Rev 0.4 March 20, 2013 12

Product Technical Specification

2.3. Block Diagrams

Figure 1. AirPrime AR7550 Block Diagram

41124764188 Rev 0.41 March 20, 2013 13

3. Hardware Specifications

3.1. Environmental Specifications

The environmental specification for both operating and storage of the AirPrime AR7550 embedded
modules are defined in the table below.

Table 4. AirPrime AR7550 Environmental Specifications

Parameter Temperature Range Operating Class

-30°C to +75°C Class A

Ambient Operating Temperature

Ambient Storage Temperature -40°C to +90°C ---

Ambient Humidity 95% or less ---

-40°C to -30°C
+75°C to +85°C

Class B

Class A is defined as the operating temperature range that the device:

 Shall exhibit normal function during and after environmental exposure.
 Shall meet the minimum requirements of 3GPP, 3GPP2 or appropriate wireless standards.

Class B is defined as the operating temperature range that the device:

 Shall remain fully functional during and after environmental exposure
 Shall exhibit the ability to establish a voice, SMS or DATA call (emergency call) at all times

even when one or more environmental constraint exceeds the specified tolerance.

 Unless otherwise stated, full performance should return to normal after the excessive

constraint(s) have been removed.

3.2. Electrical Specifications

This section provides details for some of the key electrical specifications of the AirPrime AR7550
embedded modules.

3.2.1. Absolute Maximum and ESD Ratings

This section defines the Absolute Maximum and Electrostatic Discharge (ESD) Ratings of the
AirPrime AR7550 embedded modules.

Warning:

Table 5. AirPrime AR7550 Absolute Maximum Ratings

Parameter Min Max Units

VBATT Power Supply Input - 5.0 V

VIN Voltage on any digital input or output pin - VCC_1v8+0.5 V

IIN Latch-up current -100 100 mA

4112476 Rev 0.4 March 20, 2013 14

If these parameters are exceeded, even momentarily, damage may occur to the device.

Product Technical Specification

Parameter Min Max Units

Maximum Voltage applied to antenn a interface pins

Primary Antenna - 36 V

VANT

ESD Ratings

RX2 Antenna - 36 V

GNSS Antenna - 36 V

ESD1

1 The ESD Simulator configured with 330pF, 1000.

Caution: The AirPrime AR7550 embedded modules are sensitive to Electrostatic Discharge. ESD

Primary, RX2 and GNSS antenna pads - Contact - ± 8 kV

All other signal pads - Contact - ± 1.5 kV

countermeasures and handling methods must be used when handling the AirPrime AR7550
devices.

3.3. Mechanical Specifications

3.3.1. Physical Dimensions and Connection Interface

The AirPrime AR7550 embedded modules are a Land Grid Array (LGA) form factor device. The
device does not have a System or RF connectors. All electrical and mechanical connections are made
via the 303 pad LGA on the underside of the PCB.

Table 6. AirPrime AR7550 Embedded Module Dimensions

Parameter Nominal Max Units

Overall Dimension 32 x 37 32.25 x 37.25 mm

Overall Module Height 3.64 3.89 mm

PCB Thickness 1.6 1.76 mm

Flatness Specification - 0.1 mm

Weight tbd - g

Note: The dimensions in Error! Reference source not found. are accurate as of the release date of this

document.

41124764188 Rev 0.41 March 20, 2013 15

Product Technical Specification

3.3.2. Mechanical Drawing

Figure 2. AR55x Assembly Drawing

Figure 3. AirPrime AR7550 Mechanical Dimensions Drawing

Note: The dimensions in Error! Reference source not found. are preliminary and subject to change.

41124764188 Rev 0.41 March 20, 2013 16

Product Technical Specification

3.3.3. Footprint

The AirPrime AR7550 device LGA footprint is a 303 pad array of 0.9mm, 1.45mm, and 1.90mm pads.
The following drawing illustrates the device footprint. The application footprint is recommended to
mirror the device footprint as illustrated in the following drawing (subject to change).

Figure 4. AirPrime AR7550 Footprint

Figure 5. AirPrime AR7550 Recommended Application Land Pattern

41124764188 Rev 0.41 March 20, 2013 17

Product Technical Specification

3.3.4. Thermal Consideration

The AirPrime AR7550 device is designed to work over an extended temperature range. In order to do
this efficiently a method of sinking heat from the product is recommended.

Refer to application notes (TBD) for details.

Figure 6. AirPrime AR7550 Heatsink Contact Area

41124764188 Rev 0.41 March 20, 2013 18

4. RF Specification

This section presents the WWAN RF interface of the AirPrime AR7550 series of embedded modules.
The specifications for the LTE, CDMA and WCDMA interfaces are defined.

4.1. LTE RF Interface

This section presents the LTE RF Specification for the AirPrime AR7550.

4.1.1. LTE Max TX Output Power

The Maximum Transmitter Output Power of the AirPrime AR7550 embedded modules are specified in
the following table.

Table 7. AirPrime AR7550 Maximum LTE Transmitter Output Power

Band Frequency Band

Nomi
nal
Max
TX
Outp
ut
Powe
r

+23
dB

Tolera
nce

+1/‐2
dB

Band 4

4112476 Rev 0.4 March 20, 2013 19

Product Technical Specification

Band Frequency Band

Nomi
nal
Max
TX
Outp
ut
Powe
r

Tolera
nce

Band 13 776 MHz to 787 MHz

4.1.2. LTE RX Sensitivity

The Minimum Receiver Sensitivity of the AirPrime AR7550 embedded modules are specified in the
following table.

Table 8. AirPrime AR7550 Minimum LTE Receiver Sensitivity

Band Frequency Band Minimum RX Downlink Criteria

Band 4 1710 MHz to 1755 MHz tbd tbd

Band 7 2500 MHz to 2570 MHz tbd tbd

Band 13 746 MHz to 757 MHz tbd tbd

4.2. CDMA RF Interface

This section presents the CDMA RF Specification for the AirPrime AR7550 embedded modules.
AirPrime AR7550 devices are designed to be compliant with 3GPP2 C.S0011 Rev A and 3GPP2
C.S0033 Rev A v1.0. Parameters specified differently for the reference standard are identified below.

4.2.1. CDMA Max TX Output Power

The Maximum Transmitter Output Power of the AirPrime AR7550 embedded module is specified in
the following table.

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Product Technical Specification

Table 9. AirPrime AR7550 Maximum CDMA Transmitter Output Power

Band Class Frequency Band Nominal Max TX Output Power Tolerance

BC0 800 MHz

BC1 1900 MHz

+24 dBm

+1.5/-1 dB (Class A)
+1.5/-2 dB (Class B)

4.2.2. CDMA RX Sensitivity

The Minimum Receiver Sensitivity of the AirPrime AR7550 embedded module is specified in the
following table.

Table 10. AirPrime AR7550 Minimum CDM A Receiver Sensitivity

Band Class Frequency Band Minimum RX downlink Criteria

BC0 800 MHz

BC1 1900 MHz

-106 dBm (Class A)

-104 dBm (Class B)

Less than 0.5% FER

4.3. WCDMA RF Interface

This section presents the WCDMA RF Specification for the AirPrime AirPrime AR7550 embedded

modules.

4.3.1. WCDMA Max TX Output Power

The Maximum Transmitter Output Power of the AirPrime AR7550 embedded module are specified in
the following table.

Table 11. AirPrime AR7550 Maximum WCDMA Transmitter Output Power

Band Frequency Band

II (1900/PCS) 1850 MHz to 1910 MHz

V (850/CELL) 824 MHz to 849 MHz

Nominal Max TX Output
Power

+23.5 dBm

Tolerance

+1.5/-1 dB (Class A)
+1.5/-2 dB (Class B)

4.3.2. WCDMA RX Sensitivity

The Minimum Receiver Sensitivity of the AirPrime AR7550A embedded module are specified in the
following table.

Table 12. AirPrime AR7550 Minimum WCDMA Receiver Sensitivity

Band Frequency Band Minimum RX Downlink Criteria

-106 dBm (Class A)

II (1900/PCS) 1930 MHz to 1990 MHz

V (850/CELL) 869 MHz to 894 MHz

-105 dBm (Class B)

-107 dBm (Class A)

-106 dBm (Class B)

BER < 0.001

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Product Technical Specification

4.4. WWAN Antenna Interface

The specification for the WWAN Antenna Interface of the AirPrime AR7550 embedded modules are
defined in the table below.

Table 13. AirPrime AR7550 WWAN Antenna Characteristics

Characteristics

Frequency (MHz)

Impedance RF 50 

VSWR max

Maximum Voltage

Note: RX2 Antenna port is RX only, RX parameters in the above tables are also applicable.

Table 14. WWAN Antenna Interface Pads

Pad Name Direction Function

BA11 GND Primary Antenna Ground

BA12 PRIMARY_ANT Input/Output Primary Antenna Interface

BA13 GND Primary Antenna Ground

BA7 GND Diversity Antenna Ground

BA8 DIVERSITY_ANT Input Diversity Antenna Interface

BA9 GND Diversity Antenna Ground

CDMA BC0,
WCDMA B5

TX 824-849 1850-1910 1710 – 1755 777 – 787

RX 869-894 1930-1990 2110 – 2155 746 – 756

RX 2:1

TX 2:1

Primary Antenna – 36 Volts

RX2 Antenna – 36 Volts (LTE MIMO: tbd)

CDMA BC1,
WCDMA B2

LTE B4 LTE B13

4.4.1. WWAN Antenna Recommendations

The table below defines the key characteristics to consider for antenna selection.

Table 15. AirPrime AR7550 WWAN Antenna Recommendations

Characteristics

Frequency (MHz)

Impedance

VSWR max

Polarization Linear, vertical

Typical radiated gain 0 dBi in one direction at least

CDMA BC0,
WCDMA B5

TX 824-849 1850-1910 1710 – 1755 777 – 787

RX 869-894 1930-1990 2110 – 2155 746 – 756

RF 50 

DC 10 k ±1k

RX 1.5: 1

TX 1.5: 1

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CDMA BC1,
WCDMA B2

LTE B4 LTE B13

Product Technical Specification

4.5. Primary Antenna Diagnostics

The primary antenna diagnostic feature allows the AirPrime AR7550 embedded module to determine
if the primary antenna connected to the module is: open, shorted or normal. The antenna connected
to this interface needs to have a DC resistance to ground of 10 k ± 1k embedded inside.

The ARx55x FW accepts two limits which are used to evaluate the status of the antenna, representing

the short and open thresholds. Refer to [7] for the syntax of AT+ANTLIMT.

Table 16. Primary Antenna ADC Characteristics

Min Nom Max Units

ADC Voltage Range 0 0.9 1.8 Volts

Resolution - 15 Bit

ADC Values 0 16383

Voltage/ADC step ~0.0011 Volts

1 Assumes 10k Nominal DC resistance in the attached antenna and internal to AirPrime AR7550 device

The following example illustrates the Antenna states and resistance values for a typical limit setting.

AT+ANTLIMT=1,839,1088

Table 17. Primary Antenna Diagnostics Ranges

Antenna State Min ADC Max ADC Antenna Resistance R ange

Short 0 839 ~  7 k

Normal 841 1086 7 k < x < 13 k
Open 1088 1900  13 k

Note: Highlighted numbers in the table above are progra mmed as shortLim and openLim using the

+ANTLIMT command.

4.6. RX2 Antenna Diagnostics

The RX2 antenna diagnostic feature allows the AirPrime AR75500 to determine if the RX2 antenna
connected to the module is: open, shorted or normal. The antenna connected to this interface needs
to have a DC resistance to ground of 10 k ± 1k embedded inside.

The AirPrime AR7550 FW accepts two limits which are used to evaluate the status of the antenna,

representing the short and open thresholds. Refer to [7] for the syntax of AT+ANTLIMT.

Table 18. RX2 Antenna ADC Characteristics

Min Nom Max Units

ADC Voltage Range 0 0.9 1.8 Volts

Resolution - 15 Bit

ADC Values 0 16383

Voltage/ADC step ~0.0011 Volts

1 Assumes 10k Nominal DC resistance in the attached antenna and internal to AirPrime AR7550 device

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Product Technical Specification

The following example illustrates the Antenna states and resistance values for a typical limit setting.

AT+ANTLIMT=2,839,1088

Table 19. RX2 Antenna Diagnostics Rang es

Antenna State Min ADC Max ADC Antenna Resistance R ange

Short 0 839 ~  7 k

Normal 841 1086 7 k < x < 13 k
Open 1088 1900  13 k

Note: Highlighted numbers in the table above are progra mmed as shortLim and openLim using the

+ANTLIMT command.

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5. GNSS Specification

The AirPrime AR7550 embedded module includes optional Global Navigation Satellite System
(GNSS) capabilities via the Qualcomm gpsOne Gen8 Engine, capable of operation in assisted and
stand-alone GPS modes as well as GPS+GLONASS mode.

5.1. GNSS

The GNSS implementation supports GPS L1 operation and GLONASS L1 FDMA operation.

Table 20. GNSS Characteristics

Parameter Value

Standalone or MS Based Tracking Sensitivity tbd

Sensitivity

Accuracy in Open Sky (1 Hz tracking) <2m CEP-50

Total number of SV available ~30 SVs

Support for Predicted Orbits Yes

Predicted Orbit CEP-50 Accuracy 5 m

Standalone Time To First Fix (TTFF)

Number of channels tbd

GNSS Message Protocols NMEA

Cold Start Sensitivity tbd

MS Assisted Synchronous A-GNSS Acquisition Sensitivity tbd

Super Hot 1 s

Warm 29 s

Cold 32 s

Note: Acquisition/Tracking Sensitivity performance figures assume open sky w/ active patch GNSS

antenna and a 2.5 dB Noise Figure.

5.2. GNSS Antenna Interface

The specification for GNSS Antenna Interface is defined in the table below. The AirPrime AR7550
provides biasing for an active antenna as well as onboard circuitry for diagnostics of this antenna
interface.

Table 21. GNSS Antenna Interface Characteristics

Characteristics GNSS

Frequency

RF Impedance 50 

VSWR max RX

LNA Bias Voltage 4.4 – 4.9V, 5.25V (No Load)

LNA Current Consumption 50 mA Max

Maximum Voltage applied to antenna 36 Volts

GPS L1 (Wideband) 1575.42 ± 20 MHz

Glonass L1 FDMA 1597.5 – 1605.8 MHz

2:1

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Product Technical Specification

Minimum isolation between the GNSS and WWAN Antenna must be 10 dB for the AirPrime AR7550.

Table 22. GNSS Antenna Interface Pads

Pad Name Direction Function

BA4 GND GNSS Antenna Ground

BA5 GNSS_ANT Input GNSS Antenna Interface

BA6 GND GNSS Antenna Ground

5.2.1. GNSS Antenna Recommendations

The table below defines the key characteristics to consider for antenna selection.

Table 23. GNSS Recommende d Antenna Characteristics

Characteristics GNSS

Frequency

RF Impedance 50 

VSWR max RX 1.5: 1

LNA Bias Voltage 4.4 – 4.9V

LNA Noise Figure 2.0 dB Max

LNA Current Consumption 50 mA Max

Antenna System Gain (Antenna + LNA - Cable) 20 – 24 dB

Polarization Right Hand Circular Polarization

GPS L1 (Wideband) 1575.42 ± 20 MHz

Glonass L1 FDMA 1597.5 – 1605.8 MHz

5.3. GNSS Antenna Diagnostics

The GNSS Antenna Diagnostic feature measures the current drawn by an active GNSS antenna to
determine the state of this antenna interface. Based on the current draw an assessment of open,
short, normal or over-current is made. If an over-current is detected, the bias for the active antenna is
removed to eliminate the fault for drawing excess current which could potentially damage the antenna.

The limits between open/normal and normal/short can be set by the application through an AT
Command.

ADC Va lue

GNSS Antenna State

<

openLim

Open Normal Short

< >

>

shortLim

The Over Current limit is set by hardware and cannot be altered.

Table 24. GNSS Antenna Diagnosti cs Ranges

Control State Min Max Units

HW Over Current 78 100 mA

The GNSS antenna supply is powered from VBATT through a boost regulator.

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Product Technical Specification

The following table identifies some key VGNSS_ANT current draw values and the associated ADC
values.

Table 25. VGNSS_ANT Current Draw

I (mA) Nominal

0 337

5 612

10 936

15 1242

20 1558

25 1877

30 2194

35 2494

40 2821

45 3188

50 3444

55 3747

60 4065

65 4292

70 4319

The graph below illustrates the relationship between current drawn on VGNSS_ANT vs the ADC
readings used to monitor the GNSS Antenna status.

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Product Technical Specification

Figure 7. VGNSS_ANT vs. ADC Readings Relationship

PMIC

GNSS_ANT_ADC

MPP_02

LGA

VBATT

0~4.35V

BOOSTREG

VIN VOUT

BOOST_CTRL

150K

5V

FB

PM8018

GPIO_59

GPIO_09

GNSSPWR_EN

ILIM_OC_N

10K

330m

Vout

S+ S‐

200V/V

Converter

ILim

VIN VOUT

FLAGB

ON

CurrentLimit=75mA

VGNSS

5V

MDM9X15

GPIO_69

Figure 8. GNSS Power Supply and Antenna Diagnostics Block Diagram

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ILIM_EN

Product Technical Specification

5.4. Current Consumption

The table below summarizes some key current consumption values for various modes of the AirPrime
AR7550 devices.

Table 26. AirPrime AR7550 Current Consumption Values

Mode Parameter Typical Max Units

Maximum TX Output – 1xRTT/1xEVDO - tbd mA

On Call – CDMA

On Call – WCDMA

On Call – LTE

Idle – CDMA

Idle – WCDMA

Idle – LTE

Sleep Mode

Off Power OFF Current tbd tbd A

GNSS

+0dBm TX Output – 1xRTT tbd - mA

+0dBm TX Output – 1xEVDO tbd - mA

Maximum TX Output – WCDMA/HSPA - tbd mA

+0dBm TX Output – WCDMA tbd - mA

+0dBm TX Output – HSPA tbd - mA

Maximum TX Output - tbd mA

+0dBm TX Output tbd - mA

Registered

Searching for network – CDMA tbd - mA

Registered

Searching for network – WCDMA tbd - mA

Registered

Searching for network – LTE tbd - mA

Average current, QPCH, SCI=2 - tbd mA

Average current, WCDMA, DRX=8 - tbd mA

Average current, LTE - tbd mA

Acquisition (Airplane mode, cold start) tbd mA

Tracking (Registered) tbd mA

Powering an Active Antenna from VGNSS_ANT tbd mA

USB Enumerated tbd - mA

USB Not Enumerated tbd - mA

USB Enumerated tbd - mA

USB Not Enumerated tbd - mA

USB Enumerated tbd - mA

USB Not Enumerated tbd - mA

1 This is the additional current draw on VBATT for 10mA consumption by Active LNA from VGNSS_ANT. Higher current
consumption by the antenna will result in higher consumption on VBATT.

5.5. Digital IO Characteristics

The Digital IO characteristics are defined in the table below. These apply to GPIOs, UART, LED,
SDIO and PCM/I2S.

Table 27. Digital IO Characteristics

Parameter Comments Min Typ Max Units

VIH

41124764188 Rev 0.41 March 20, 2013 29

High level input
voltage

CMOS/Schmitt 0.65* VCC_1V8 – VCC_1V8+0.3 V

Product Technical Specification

Parameter Comments Min Typ Max Units

VIL

VOH

VOL

IOH

IOL

I

OH-LED

I

OL-LED

I

IHPD

I

ILPU

IL

CIN

C

IN-LED

Low level input
voltage

High level
output voltage

Low-level output
voltage

High level
output current

Low Level
output current

High level
output current

Low Level
output current

Input high
leakage current

Input low
leakage current

Input leakage
current

Input
capacitance

Input
capacitance

CMOS/Schmitt -0.3 – 0.35* VCC_1V8 V

CMOS, at pin rated drive
strength

CMOS, at pin rated drive
strength

VOH = VCC_1V8 – 0.45
V

VCC_1V8 - 0.45 – VCC_1V8 V

0 – 0.45 V

– – 6 mA

VOL = 0.45 V -6 – – mA

LED signal only – – – mA

LED signal only -3 – 20 mA

With pull-down 5 30 µA

With pull-up -30 -5 µA

VIO = max,
VIN = 0 V to VIO

-0.3 – +0.35 µA

LED signal only

– – 7 pF

LED signal only – – 5 pF

Caution: Digital IOs shall not be pulled-up to an external voltage as this may cause VCC_1V8 to not go low

when the AirPrime AR7550 device is powered down. Also, this would partially bias the AirPrime
AR7550 device which could potentially damage the device or result in GPIOs being set to
undetermined levels.

5.6. Internal Device Frequencies

The table below summarizes the frequencies generated within the AirPrime AR7550. This table is
provided for reference only to the device integrator.

Table 28. Internal Device Frequencies

Subsystem/Feature Frequency Units

Real Time Clock 32.768 kHz

8,

PCM Audio interface (Primary PCM Master Mode) [TBD]

I2C Interface 400 kHz

PMIC switching power supplies tbd MHz

GNSS Antenna bias switching supply 3.5 MHz

128,
2048

kHz

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Product Technical Specification

Subsystem/Feature Frequency Units

Fundamental clock, codec, TCXO_OUT 19.2 MHz

PLL tbd MHz

USB

12,
480

Mb/s

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6. Baseband Specification

6.1. Power Supply

The AirPrime AR7550 embedded module is powered via a single regulated DC power supply, 3.7V
nominal. The power supply requirements can be found in the following table.

Table 29. Power Supply Requirements

Power Supply Min Typ Max Units

Main DC Power Input Range 3.4 3.7 4.2 V

Power Supply Ripple

Maximum Current draw AR7550 - - tbd mA

AirPrime AR7550 does not support USB bus-powered operation. DC power must be supplied via the
VBATT input.

0 to 1kHz - - 200 mVpp

>1kHz - - 50 mVpp

Table 30. Power Supply Pads

Pad Name Direction Function If Unused

EA2 VBATT Input Power Supply Input Must Be Used

EB2 VBATT Input Power Supply Input Must Be Used

EC2 VBATT Input Power Supply Input Must Be Used

6.1.1. Under-Voltage Lockout (UVLO)

The power management section of the AirPrime AR7550 includes an under-voltage lockout circuit that
monitors supply and shuts down when VBATT falls below the threshold.

Figure 9. Under-Voltage Lockout (UVLO) Diagram

The AirPrime AR7550 will power down and remain off until the level of VBATT returns to the valid
range and the ON/OFF signal is active.

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Product Technical Specification

Note: If the AirPrime AR7550 device has 6 UVLO events without a valid power down or reset sequence, it

enters a mode in which only the DM port enumerates on the USB.

Table 31. UVLO Threshol ds

Description Value Units

Rising threshold 2.725 V

UVLO

Falling threshold 2.55 V

Minimum Duration below Falling threshold 1.0 uS

6.2. VCOIN

The AirPrime AR7550 provides an interface for a coin cell to maintain the internal RTC when VBATT
is removed from the AirPrime AR7550 device. Whenever VBATT is applied the RTC is powered from
the VBATT supply. The AirPrime AR7550 also supports charging of a coin cell if connected to this
interface.

Table 32. VCOIN Pad

Pad Name Direction Function If Unused

AC11 VCOIN Input /Output Voltage Input/Charging output Leave Open

The table below defines the specifications of this interface.

Table 33. VCOIN Interface Specification

VCOIN Min Typ Max Units

DC Power Input Range TBD TBD TBD V

Current Draw 1.1 2.0 A

The table below defines the VCOIN charging specifications.

Table 34. VCOIN Charging Specifications

VCOIN Charging Specs Comments Min Typ Max Units

Target regulator voltage1 VIN > 2.5 V, ICHG = 100 A TBD TBD TBD V

Target series resistance2 800 – 2100 

Coin cell charger voltage error ICHG = 0 A -5 – +5 %

Coin cell charger resistor error -20 – +20 %

Dropout voltage3 ICHG = 2 mA – – 200 mV

Ground current, charger enabled
VBAT = 3.6 V, T = 27 ºC
VBAT = 3.2 to 4.2 V

IC = off; VCOIN = open

–
–

4.5
–

–
8

A
A

1. Valid regulator voltage settings are 2.5, 3.0, 3.1, and 3.2 V.

2. Valid series resistor settings are 800, 1200, 1700, and 2100 .

3. Set the input voltage (VBAT) to 3.5 V. Note the charger output voltage; call this value V0. Decrease the input voltage
until the regulated output voltage drops 100 mV (until the charger output voltage = V0 - 0.1 V). The voltage drop across
the regulator under this condition is the dropout voltage (Vdropout = VBAT - the charger output voltage).

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Product Technical Specification

6.3. ON/OFF Control

The AirPrime AR7550 provides an interface for controlling the device ON/OFF state.

Table 35. ON/OFF Control Pads

Pad Name Direction Function If Unused

BB1 ON/OFF Input ON/OFF Control Must Be Used

The ON/OFF signal is internally pulled up to an internal 1.8V reference voltage. An open drain
transistor should be connected to this pin to generate a low pulse. This pin should not be driven high
external to the AirPrime AR7550 embedded module.

Table 36. ON/OFF Internal Pull-Up

Signal Parameter Min Typ Max Units

ON/OFF Internal Pull-up - 200 - k

6.3.1. ON/OFF Timing

The ON/OFF pin is a low pulse toggle control. The first pulse powers the AirPrime AR7550 ON, a
second pulse instructs the AirPrime AR7550 to begin the Shutdown process.

The diagram below illustrates the recommended application implementation for ON/OFF control.

Figure 10. Recommended ON/OFF Control

The diagram below illustrates an alternate application implementation that holds ON/OFF low during
operation.

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Product Technical Specification

Figure 11. Alternate ON/OFF Control

Table 37. Power-ON Sequence Symbol Definitions

Symbol Parameter Boot Min Typ Max

tON Turn ON Pulse duration 50 ms 100 ms

t

Turn OFF Pulse duration 50 ms 100 ms 500 ms

OFF

t

Time to Power OFF - 5 s -

pwroff

t

pwrrmv

tHI

T

pwroff

Time VBATT must be maintained after VCC_1V8
goes inactive

Time required for ON/OFF to be high prior to OFF
pulse.

0 s - -

In process 10 s -

Complete 50 ms

is the time between when a power OFF pulse is complete and when shutdown is completed by



the AirPrime AR7550 devices. This duration is network and device dependent, i.e. in a CDMA network
a power down registration is initiated by the AirPrime AR7550 device, when the acknowledgement is
received from the network power OFF completes.

Detection of power down can be accomplished by monitoring for one of the following:

 +WIND: 10 output on the AT Command interface

 USB ports are de-enumerated

The application must wait for a power down to be detected prior to removing power from the AirPrime
AR7550 device. If a timeout is required, it is recommended to be in excess of 30s prior to removing
power from the AirPrime AR7550 device.

Note: Refer to [7] for details on enabling the +WIND message for power down and +USLGRPMSK and

+USLEVTMSK for unsolicited message output.

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Product Technical Specification

6.3.3. Software-Initiated Power Down

The host application may choose to use the AT Command AT!POWERDOWN to initiate a power
down of the AirPrime AR7550 device instead of using an OFF pulse. In this scenario the ON/OFF
signal should be left open by the application. The AirPrime AR7550 device will initiate a power up
after completion of the power down if ON/OFF is low.

6.3.4. Deep Sleep

The AirPrime AR7550 embedded modules support a low power mode in which the device is
registered on the LTE/CDMA/GSM/WCDMA network and sleeps in between wake intervals where it
listens for pages.

Figure 12. Power Mode Diagram

The following table lists the parameter that defines the wake interval period for the various devices.

Table 38. Period of Wake Intervals

AR Series Device Network Standard Parameter

CDMA SCI

AR7550

WCDMA DRX

LTE DRX

The average current consumption of the AirPrime AR7550 while in this mode is defined in the Sleep
Mode portion of the current consumption tables in section 5.4 Current Consumption.

The Slot Cycle Index is the lower of the values stored in the AirPrime AR7550 or the value being
broadcast by the wireless network that the AirPrime AR7550 is registered on.

The MFRM and DRX cycle index values are broadcast by the wireless network on which the AirPrime
AR7550 embedded module is registered.

While in Deep Sleep mode the functions of the AirPrime AR7550 are limited as defined in the
following table.

Table 39. Deep Sleep Function Availability

Function Availability Conditions

Paging



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Product Technical Specification

Function Availability Conditions

GNSS - GNSS is powered down

Time measurement

USB - USB_VBUS is not applied

UART -

Digital IO - Digital IO pins maintained last state



Events that cause the AirPrime AR7550 to wake-up from Deep Sleep mode include:

 Incoming call

 Expiration of an internal timer in the AirPrime AR7550

 USB_VBUS is applied to the AirPrime AR7550

 WAKE_N is asserted (low)

 UART1 DTR is asserted (high) if UART1 DTR has been enabled as a sleep control

(AT+W32K=1,1) and AT Command Service is mapped to UART1

 GNSS location fix request is initiated from an Embedded Application

See the Ring Indicator section for more information about configuring the RI signal to notify an
external application of a wake-up event while the AR device is in sleep mode.

6.3.4.1. Sequence to Enter Deep Sleep Mode

The following list defines the sequence needed by the application to allow the AirPrime AR7550 to
enter Deep Sleep mode:

1. AR7550 has registered on the WWAN network (or callbox), and is not in a call.

2. End GNSS Tracking session.

3. Turn off GNSS Antenna bias.

4. Confirm WAKE_N is not held low (pulled-up in AirPrime AR7550).

5. Issue AT command to request AR device to enter deep sleep (AT+W32K=1,x).

6. If AT+W32K=1,1 is used, DTR must also be de-asserted to allow sleep.

7. Ensure UARTs are in the inactive state.

8. Remove VBUS from being applied to the AR device.

6.4. USB

The AirPrime AR7550 has a High Speed USB2.0 compliant, peripheral only interface.

Table 40. USB Pad Details

Pad Name Direction Function

DA7 USB_VBUS Input USB Power Supply

DB6 USB_D_P In/Out Differential data interface positive

DA6 USB_D_M In/Out Differential data interface negative

DD5 USB_ID In/Out USB ID

The AR7550 will not be damaged if a valid USB_VBUS is supplied while the main DC power is not
supplied.

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Product Technical Specification

Table 41. USB Characteristics

USB Value Units

Voltage range 2.0 – 5.25 V

USB_VBUS

1 With the AirPrime AR7550 device powered ON.

Maximum Current draw1 1 mA

Maximum Input Capacitance (Min ESR = 50 m) 10 F

6.5. UART

The AirPrime AR7550 has two UART interfaces. The primary UART is an 8-wire1 electrical interface
and the secondary UART is a 2-wire electrical interface.

Table 42. UART Pads

Pad Name Direction Function Interface If Unu sed

AD9 RXD1 Output Receive Data (UART1) UART1 Leave Open

AE6 RTS1 Input Ready To Send (UART1) UART1 Leave Open1

AD8 TXD1 Input Transmit Data (UART1) UART1 Leave Open

AE7 CTS1 Output Clear To Send (UART1) UART1 Leave Open

AF6 DCD1 Output Data Carrier Detect (UART1) UART1 Leave Open

AE5 DTR1 Input Data Terminal Ready (UART1) UART1 Leave Open

AF5 DSR1 Output Data Set Ready (UART1) UART1 Leave Open

DB2 RXD2 Output UART2 Receive Data UART2 Leave Open

DA2 TXD2 Input UART2 Transmit Data UART2 Leave Open

1 If UART1 is implemented as a 2-wire interface, RTS1 should be pulled low to disable flow control.

6.6. Ring Indicator

The Ring Indicator (RI) may be used to notify an external application of several events such as an
incoming call, timer expiration or incoming SMS.

Table 43. Ring Indicator Pad

Pad Name Dir ection Function If Unused

AD7 RI1 Output Ring Indicator Leave Open

The events which toggle the RI signal can be configured using the AT+WWAKESET command. The
duration of the RI pulse can be configured using the AT+WRID command.

The reason for the RI signal being activated can be queried using the AT+WWAKE command. Refer
to [7] for details of these AT Commands.

The RI signal is independent of the UART.

1

Includes Ring Indicator which may also be used independently of UART1.

41124764188 Rev 0.41 March 20, 2013 38

Product Technical Specification

6.7. UIM Interface

The UIM interface of the AirPrime AR7550 supports a USIM/CSIM for LTE, WCDMA, GSM and
CDMA. The UIM can be embedded internally in AR7550 and can be external to AR7550.

Table 44. UIM Pads

Pad Name Direction Function If Unused

DA5 UIM_DETECT Input Detection of an external UIM card Leave Open

DB4 UIM_VCC Output Supply output for an external UIM card Leave Open

DC3 UIM_RST Output Reset output to an external UIM card Leave Open

DA4 UIM_DAT Input /Output Data connection with an external UIM card Leave Open

DE1 UIM_CLK Output Clock output to an external UIM card Leave Open

The diagram below illustrates the recommended implementation of a UIM holder on the application.

Figure 13. Recommended UIM Holder Implementation

UIM_DETECT is used to detect the physical presence of a SIM/UIM card in the holder. It has a 3.0uA
to 30µA pull-up to 1.8V inside the AirPrime AR7550. It should be set to GND if a SIM/UIM is present.
All signals must be ESD-protected near the UIM holder.

The capacitor and two resistors should be added as placeholders to compensate for potential layout
issues. UIM_DAT trace should be routed away from the UIM_CLK trace. Keep distance from AirPrime
AR7550 to UIM-Holder as short as possible.

An ESD device specifically designed for SIM/UIM cards is recommended for UIM_VCC, UIM_RST,
UIM_CLK and UIM_DAT. i.e. SEMTECH EClamp2455K, Infineon BGF106C or NXP IP4264CZ8-20­TTL. For UIM_DETECT a low leakage ESD suppressor should be selected.

6.7.1. Internal UIM

Alternatively, a hardware option is available that includes a UIM device mounted on the AirPrime
AR7550 PCB thus eliminating the need for an external UIM holder

41124764188 Rev 0.41 March 20, 2013 39

Product Technical Specification

6.8. General Purpose IO

The AirPrime AR7550 defines 10 GPIOs for customer use.

Table 45. GPIO Interface Pads

Pad Name Pull State Function If Unused

CA10 GPIO1 Pull-Down Available-GPIO Leave Open

CA11 GPIO2 Pull-Down Available-GPIO Leave Open

CB10 GPIO3 Pull-Down Available-GPIO Leave Open

CB11 GPIO4 Pull-Down Available-GPIO Leave Open

CC7 GPIO5 Pull-Down Available-GPIO Leave Open

CC8 GPIO6 Pull-Down Available-GPIO Leave Open

CC9 GPIO7 Pull-Down Available-GPIO Leave Open

CD7 GPIO8 Pull-Down Available-GPIO Leave Open Band indicator1

CE5 GPIO9 Pull-Down Available-GPIO Leave Open Band indicator2

CF5 GPIO10 Pull-Down Available-GPIO Leave Open Band indicator3

Multiplexed
Function

Refer to the Digital IO Characteristics section for electrical characteristics of these signals.

6.8.1. AT Port Switch

The AirPrime AR7550 supports switching the active AT command port between USB and UART.

Table 46. AT Port Switch States

Pad Name State AT Po rt

AB5 AT_PORT_SW

Low (default) Available on USB

High Available on UART1

6.9. Secure Digital IO

The AirPrime AR7550 defines a 1.8V SDIO interface for future use.

Table 47. SDIO Interface Pads

Pad Name Direction Function If Unused

AA11 SDIO_DATA0 Input/Output SDIO Data bit 0 Leave Open

AA10 SDIO_DATA1 Input/Output SDIO Data bit 1 Leave Open

AB9 SDIO_DATA2 Input/Output SDIO Data bit 2 Leave Open

AB10 SDIO_DATA3 Input/Output SDIO Data bit 3 Leave Open

AB8 SDIO_CMD Output SDIO Command Leave Open

AA9 SDIO_CLK Output SDIO Clock Leave Open

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Product Technical Specification

6.10. I2C

The AirPrime AR7550 provides an I2C interface.

Table 48. I2C Interface Pads

Pad Name Direction Function If Unused

CD6 I2C_CLK Output I2C Clock output Leave Open

CC6 I2C_SDA Input/Output I2C Data Leave Open

The I2C signals are open drain outputs with 2.2 k pull-up resistors to VCC_1V8 internal to the
AirPrime AR7550.

6.11. Voltage Reference

The AirPrime AR7550 utilizes 1.8V logic. A voltage reference output for this rail is provided below.

Table 49. Voltage Reference Pad

Pad Name Direction Function If Unused

AA12 VCC_1V8 Output Voltage Reference Output Leave Open

AB12 VCC_1V8 Output Voltage Reference Output Leave Open

Table 50. Voltage Reference Characteristics

Parameter Min Typ Max Units

VCC_1V8

The VCC_1V8 signal can be used to power external circuitry and/or detect the power state of the
AirPrime AR7550 device.

Using VCC_1V8 to determine the power state is recommended when the user application wants to
disable VBATT. VBATT should not be disabled before VCC_1V8 goes inactive. To be able to detect
the power state on VCC_1V8, all logic input signals to the AirPrime AR7550device must be set low
(see Digital IO Characteristics for affected signal groups).

The VCC_1V8 signal is High-Z when the AirPrime AR7550 embedded module is powered down.

Voltage Level 1.746 1.8 1.854 V

Output Current 25 mA

6.12. RESET

The AirPrime AR7550 provides an interface to allow an external application to RESET the module as
well as an output to indicate the current RESET state or control an external device.

Table 51. Reset Interface Pads

Pad Name Direction Function If Unused

AH2 RESIN_N Input External Reset Input Leave Open

AG4 RESOUT_N Output Reset Output Leave Open

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Product Technical Specification

The RESIN_N signal is pulled-up internal to the AirPrime AR7550. An open collector transistor or
equivalent should be used to Ground the signal when necessary to RESET the module.

Note: Use of the RESIN_N signal to RESET the AirPrime AR7550 could result in memory corruption if

used inappropriately. This signal should only be used if the AirPrime AR7550 has become
unresponsive and it is not possible to perform a power cycle.

Table 52. Reset Timing

Symbol Parameter Min Typ Max

Trdet

Trlen Duration reset asserted 40 ms - 

Trdel

Figure 14. Illustration of Reset Timing When RESIN_N < Trdel

Duration of RESIN_N signal before firmware detects it
(debounce timer)

Delay between minimum Reset duration and Internal Reset
generated

- 32 ms -

- 500 ms -

Figure 15. Illustration of Reset Timing When RESIN_N Held Low > Trdet+Trdel

6.13. ADC

The AirPrime AR7550 provides two ADC inputs. The interface information is provided in the tables
below.

Table 53. ADC Interface Pads

Pad Name Direction Function If Unused

DE3 ADC0 Input Analog to Digital Converter Input Leave Open or Ground

DF2 ADC1 Input Analog to Digital Converter Input Leave Open or Ground

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Product Technical Specification

Table 54. ADC Interface Characteristics

ADC Value Units

Full-Scale Voltage Level 1.8 V

ADCx

Resolution 15 bit

Input Impedance >4 M

6.14. LED

The AirPrime AR7550 provides an LED control output signal pad. This signal is an open drain input.

Table 55. LED Interface Pad

Pad Name Direction Function If Unused

AA6 LED Output LED driver control Leave Open

Figure 16. LED Reference Circuit

The behavior of the LED signal can be modified using the AT command AT!LEDCTRL.

6.15. Audio

The AirPrime AR7550 supports both Analog and Digital audio interfaces. The following diagram
illustrates the Audio subsystem and identifies where various AT commands affect the audio
subsystem. Refer to [7] for details of the AT commands.

[Diagram tbd]

Figure 17. Audio Block Diagram

6.15.1. Analog Audio

The AirPrime AR7550 provides a mono differential analog audio interface.

Table 56. Analog Audio Interface Pads

Pad Name Direction Function Interface

CD9 AUDIO1_IN_P

CC10 AUDIO1_IN_M Microphone 1 input negative

CE6 AUDIO1_OUT_P

CE8 AUDIO1_OUT_M Speaker 1 output negative

Input

Output

Microphone 1 input positive

Speaker 1 output positive

Primary

41124764188 Rev 0.41 March 20, 2013 43

Product Technical Specification

Table 57. Analog Audio Interface Charac teristics

Analog Audio Min. Typ. Max. Units

Input Impedance 16 20 24 k

Signal Level – Differential -0.3 - 2.9 dBV

Audio IN

Audio OUT

Signal Level – Single-ended
(the unused audio signal must be tied to
GND or analog reference)

Signal Level – Differential - - dBV

Signal Level – Single-ended -0.3 - 2.9 dBV

Output Impedance -0.3 - 2.9 

Signal Drive Strength – Application Load - 600 1M k

-0.3 - 2.9 dBV

6.15.2. Digital Audio

The AirPrime AR7550 provides a 4-wire digital audio interface. This interface can be configured as
either a PCM or an I2S.

Table 58. Digital Audio Interface Pads

Pad Name Direction1

DB3 PCM_FS Output

DA3 PCM_CLK Output PCM Clock Input/Output I2S_SCLK Leave Open

DC2 PCM_DOUT Output PCM Data Out Output I2S_DOUT Leave Open

DD2 PCM_DIN Input PCM Data In Input I2S_DIN Leave Open

1 Direction when defined in Master mode.

PCM
Function

PCM Frame
Sync

Direction I2S Fun ction If Unused

Input/Output I2S_WS Leave Open

6.15.2.1. PCM

The AirPrime AR7550 PCM interface can be configured in one of two modes: primary PCM or
auxiliary PCM mode. The table below defines the configurations for each of these two modes.

Table 59. PCM Interface Configurations

Element Primary PCM Auxiliary PCM

Slot Configuration Slot-based Single

Sync type Short Long

Frequency 8 kHz

Duty Cycle 50%

Clock (Master) 2.048 MHz 128 kHz

Data formats 16-bit linear, 8-bit A-law, 8-bit m-law

AirPrime AR7550 Master/Slave Master or Slave Master

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Product Technical Specification

6.15.2.1.1. PCM Data format

The PCM data is 8 kHz and 16 bits with the following PDM bit format:

 PCM_DIN – SDDD DDDD DDDD DDVV

 PCM_DOUT – SDDD DDDD DDDD DDVV

Where:

 S – Signed bit

 D – Data

 V – Volume padding

6.15.2.1.2. Primary PCM Timing

The table and drawings below illustrate the PCM signals timing when the AirPrime AR7550 module is
operating in Primary PCM mode.

Table 60. Primary PCM Timing

Parameter Description Min Typ Max unit

T(sync) PCM_FS cycle time - 125 - µs

T(synch) PCM_FS high time - 488 - ns

T(syncl) PCM_FS low time - 124.5 - µs

T(clk) PCM_CLK cycle time - 488 - ns

T(clkh) PCM_CLK high time - 244 - ns

T(clkl) PCM_CLK low time - 244 - ns

T(susync) PCM_FS setup time high before falling edge of PCM_CLK - 122 - ns

T(hsync) PCM_FS Hold time after falling edge of PCM_CLK - - 366 ns

T(sudin) PCM_DIN setup time before falling edge of PCM_CLK 60 - - ns

T(hdin) PCM_DIN hold time after falling edge of PCM_CLK 60 - - ns

T(pdout) Delay from PCM_CLK rising to PCM_DOUT valid - - 60 ns

T(zdout) Delay from PCM_CLK falling to PCM_DOUT HIGH-Z - - 60 ns

Figure 18. PCM_FS Timing Diagram (2048 kHz Clock)

41124764188 Rev 0.41 March 20, 2013 45

Product Technical Specification

Figure 19. PCM Codec to AR Device Timing Diagram (Primary PCM)

Figure 20. AR Device to PCM Codec Timing Diagram (Primary PCM)

6.15.2.1.3. Auxiliary PCM Timing

The table and drawings below illustrate the timing of the PCM signals when the AirPrime AR7550
module is operating in Auxiliary PCM mode.

Table 61. Auxiliary PCM Timing

Parameter Description Min Typ Max unit

T(auxsync) PCM_FS cycle time - 125 - µs

T(auxsynch) PCM_FS high time 62.4 62.5 - µs

T(auxsyncl) PCM_FS low time 62.4 62.5 - µs

T(auxclk) PCM_CLK cycle time - 7.8 - µs

T(auxclkh) PCM_CLK high time 3.8 3.9 - µs

T(auxclkl) PCM_CLK low time 3.8 3.9 - µs

T(suauxsync) PCM_FS setup time high before falling edge of PCM_CLK 1.95 - - ns

T(hauxsync) PCM_FS Hold time after falling edge of PCM_CLK 1.95 - - ns

T(sudin) PCM_DIN setup time before falling edge of PCM_CLK 70 - - ns

T(hauxdin) PCM_DIN hold time after falling edge of PCM_CLK 20 - - ns

T(pauxdout) Delay from PCM_CLK rising to PCM_DOUT valid - - 50 ns

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Product Technical Specification

Figure 21. PCM_FS Timing Diagram (128 kHz Clock)

Figure 22. PCM Codec to AR Device Timing Diagram (Auxiliary PCM)

Figure 23. AR Device to PCM Codec Timing Diagram (Auxiliary PCM)

6.15.2.2. I2S

The AirPrime AR7550 I2S interface can be used to transfer serial digital audio to/from an external
stereo DAC/ADC. The I2S interface is a 4-wire interface: serial clock (I2S_SCLK), word select
(I2S_WS), serial uplink data (I2S_DIN), and serial downlink data (I2S_DOUT).

The AirPrime AR7550 I2S interface can be configured as a master or slave and either transmitter or
receiver.

A high-level timing diagram of the I2S signals is presented below.

41124764188 Rev 0.41 March 20, 2013 47

8

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4

Product Technical Specification

6.16. SPI Bus

The AirPrime AR7550 embedded module provides one SPI bus (4-wire interface).

SPI bus interface includes:

 A CLK signal

 An O signal

 An I signal

 A CS (Chip Select) signal

6.16.1. Characteristics

The following features are available on the SPI bus:

 Master-only mode operation

 SPI speed is from 128 kbit/s to 26 Mbit/s in master mode operation

 4-wire interface

 4 to 32 (TBD) bits data length.

6.16.2. SPI Configuration

Table 62. SPI Configuration

Operation Maximum Speed

Master 26Mb/s 0,1,2,3 full

For the 4-wire configuration, SPIx-I/O is used as output only, SPIx-I is used as input only (TBC by
firmware).

SPI-Mode

Duplex 4-wire Type

SPIx-CLK;
SPIx-IO;
SPIx-I;
SPIx_CS

6.16.3. SPI Waveforms

The following figure shows waveforms for SPI transfer with 4-wire configuration.

Figure 25. 4-Wire Configuration SPI Transfer

41124764188 Rev 0.41 March 20, 2013 49

8

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411247641

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Rev 0.41

March

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5

Product Technical Specification

6.17. HSIC Bus

The AirPrime AR7550 embedded module provides one HSIC bus (2-wire interface).

HSIC bus interface includes:

 HSIC strobe signal

 HSIC data signal

 Calibration pad for HSIC port signal

6.17.1. HSIC Pin Description

Refer to the following table for the HSIC interface pin description.

Table 65. HSIC Pin Description

Signal Pin # I/O I/O Type Reset State Description

HSIC_STB AA2 B 1V2 Z HSIC strobe signal

HSIC_DATA AA3 B 1V2 Z HSIC data

HSIC_CAL AA4 B 1V2 Z HSIC calibration pad

6.17.2. HSIC Waveforms

The following figure shows waveforms for HSIC signal sample.

Figure 27. HSIC Signal Sample Waveforms

41124764188 Rev 0.41 March 20, 2013 51

Product Technical Specification

6.17.3. Application

A 4-wire SPI configuration has the input and output data lines disassociated.

Figure 28. Example of HSIC Bus Application

Note 1: Trace length to 10cm maximum

2: Skew between data and strobe signals < 15ps, and

3: Connect HSIC_Ready to HSIC_RST_N of the HSIC device.

41124764188 Rev 0.41 March 20, 2013 52

Product Technical Specification

6.18. Temperature Monitoring

The AirPrime AR7550 has internal temperature monitoring of both the PMIC device and the Power
Amplifier devices.

current_temp < TEMP_HI_WARN

current_temp > TEMP_HI_WARN

Normal

current_temp < TEMP_HI_NORM

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High Temperature

Critical

(Low power mode)

current_temp > TEMP_HI_CRIT

High Temperature

Warning

Low Temperature

Critical

(Low power mode)

Application asserts ON/OFF

Or

Issues AT!POWERDOWN

Power off.

Handled by

Power State

state machine.

Application asserts ON/OFF

Or

Issues AT!POWERDOWN

Table 66. Temperature Monitoring States

State Description Threshold1

Normal

High
Temperature
Warning

High
Temperature
Critical

Low
Temperature
Critical

Both PMIC and PA
Thermistors are
between

Either PMIC or PA
Thermistor has
exceeded

Either PMIC or PA
Thermistor has
exceeded

Either PMIC or PA
Thermistor has
descended past

TEMP_HI_NORM +85

TEMP_LO_NORM -40

TEMP_HI_WARN +95

TEMP_HI_CRIT 140

TEMP_HI_CRIT -45

Default Temp
value (°C )

Functionality

All

All –
Warning message output

on AT Command port

Low Power Mode – Device
will only make Emergency
calls

Low Power Mode – Device
will only make Emergency
calls

1 There are two sets of thresholds: PATEMP for PA Thermistor, and PCTEMP for PMIC Thermistor.

To restore full operation, temperature readings for both the PA and PMIC Thermistors must be within
the Normal or High Temperature Warning state thresholds.

41124764188 Rev 0.41 March 20, 2013 53

7. Routing Constraints and
Recommendations

Layout and routing of the AirPrime AR7550 device in the application is critical to maintaining the
performance of the radio. The following sections provide guidance to the developer when designing
their application to include an AirPrime AR7550 device and achieve optimal system performance.

7.1. RF Routing Recommendations

To route the RF antenna signals, the following recommendations must be observed for PCB layout:

The RF signals must be routed using traces with a 50  characteristic impedance.

Basically, the characteristic impedance depends on the dielectric constant (εr) of the material used,
trace width (W), trace thickness (T), and height (H) between the trace and the reference ground plane.

In order to respect this constraint, Sierra Wireless recommends that a MicroStrip structure be used
and trace width be computed with a simulation tool (such as AppCAD, shown in the figure below and
available free of charge at http://www.avagotech.com).

Figure 30. AppCAD Screenshot for Microstrip Design Power Mode Diagram

The trace width should be wide enough to maintain reasonable insertion loss and manufacturing
reliability. Cutting out inner layers of ground under the trace will increase the effective substrate
height; therefore, increasing the width of the RF trace.

Caution: It is critical that no other signals (digital, analog, or supply) cross under the RF path. The figure

below shows a generic example of good and poor routing techniques.

4112476 Rev 0.4 March 20, 2013 54

Product Technical Specification

Poor routing Correct routing

The yellow traces cross the RF trace. There is no signal around the RF path.

Figure 31. RF Routing Examples

 Fill the area around the RF traces with ground and ground vias to connect inner ground layers

for isolation.

 Cut out ground fill under RF signal pads to reduce stray capacitance losses.

 Avoid routing RF traces with sharp corners. A smooth radius is recommended.

E.g. Use of 45° angles instead of 90°.

 The ground reference plane should be a solid continuous plane under the trace.

 The coplanar clearance (G, below) from the trace to the ground should be at least the trace

width (W) and at least twice the height (H). This reduces the parasitic capacitance, which
potentially alters the trace impedance and increases the losses.
E.g. If W = 100 microns then G = 200 microns in an ideal setup. G = 150 microns would also
be acceptable is space is limited.

Figure 32. Coplanar Clearance Example

Note: The figure above shows several internal ground layers cut out, which may not be necessary for

every application.

41124764188 Rev 0.41 March 20, 2013 55

Product Technical Specification

Figure 33. Antenna Microstrip Routing Example

7.2. Power and Ground Recommendations

Power and ground routing is critical to achieving optimal performance of the AirPrime AR7550 devices
when integrated into an application.

Recommendations:

 Do not use a separate GND for the Antennas

 Connections to GND from the AirPrime AR7550 should be flooded plane using thermal reliefs

to ensure reliable solder joints.

 VBATT is recommended to be routed as a wide trace(s) directly from the 4V supply to the

LGA pad.

7.3. Antenna Recommendations

The AirPrime AR7550 devices are designed to provide diagnostics status of the antennas connected
to it.

 The Primary antenna interface is optimized for a multiband cellular antenna with a 10 k DC

impedance between the antenna element and the ground reference.

 The GNSS antenna interface is optimized for a 5V active GNSS antenna supporting the GPS

L1 and GLONASS L1 FDMA bands. Refer to the GNSS Antenna Diagnostics section.

Connecting the antenna ground reference to the vehicle chassis is not recommended since that has
been known to cause noise from the engine to couple into the audio of the device. It is ultimately up to
the integrator to evaluate this performance.

41124764188 Rev 0.41 March 20, 2013 56

Product Technical Specification

7.4. Interface Circuit Recommendations

The recommended interface implementation is to use open-drain non-inverting buffers with pull-ups to
the appropriate voltage reference. This allows a host processor operating at a different voltage to
communicate with the AirPrime AR7550 using the appropriate voltage levels.

The figure below is a reference circuit for a digital input signal to the AirPrime AR7550 device.

Figure 34. AirPrime AR7550 Input Reference Circuit

The figure below is a reference circuit for a digital output signal from the AirPrime AR7550 device.

Figure 35. AirPrime AR7550 Output Reference Circuit

Refer to Chapter Error! Reference source not found. Error! Reference sou rce not found. section

to identify the appropriate reference voltage and direction of the specific signals.

The open-drain non-inverting buffer used in the reference circuits above is the OnSemi NL17SZ07.

Tip: The NL17SZ07 is over-voltage tolerant on the inputs. It may be possible to power all the buffers

from the 1.8V reference voltage output. Review the digital output characteristics of the applications
drivers and the Input characteristics of the buffer selected to determine if this would work in your
application.

If a Digital IO signal is used bidirectional in the application then a bidirectional buffer or bidirectional
level translator is needed.

41124764188 Rev 0.41 March 20, 2013 57

8. Regulatory Information

8.1. Important Notice

Because of the nature of wireless communications, transmission and reception of data can never be
guaranteed. Data may be delayed, corrupted (i.e., have errors) or be totally lost.

Although significant delays or losses of data are rare when wireless devices such as the Sierra
Wireless modem are used in a normal manner with a well-constructed network, the Sierra Wireless
modem should not be used in situations where failure to transmit or receive data could result in
damage of any kind to the user or any other party, including but not limited to personal injury, death,
or loss of property. Sierra Wireless and its affiliates accept no responsibility for damages of any kind
resulting from delays or errors in data transmitted or received using Sierra Wireless modem, or for
failure of the Sierra Wireless modem to transmit or receive such data.

Safety and Hazards

Do not operate the AR7550 modem:

 In areas where blasting is in progress
 Where explosive atmospheres may be present including refueling points, fuel depots, and

chemical plants

 Near medical equipment, life support equipment, or any equipment which may be susceptible

to any form of radio interference. In such areas, the AR Series device MUST BE POWERED
OFF. Otherwise, the AR Series device can transmit signals that could interfere with this

equipment

 In an aircraft, the AR Series device MUST BE POWERED OFF. Otherwise, the AR Series

device can transmit signals that could interfere with various onboard systems and may be
dangerous to the operation of the aircraft or disrupt the cellular network. Use of cellular phone
in aircraft is illegal in some jurisdictions. Failure to observe this instruction may lead to
suspension or denial of cellular telephone services to the offender, or legal action or both.

 Some airlines may permit the use of cellular phones while the aircraft is on the ground and

the door is open. The AR Series device may be used normally at this time.

8.2. Important Compliance Information for USA
OEM Integrators

The AR Series device is granted with a modular approval for mobile applications. Integrators may use
the AR Series device in their final products without additional FCC/IC (Industry Canada) certification if
they meet the following conditions. Otherwise, additional FCC/IC approvals must be obtained.

1. At least 20cm separation distance between the antenna and the user’s body must be
maintained at all times.

2. To comply with FCC/IC regulations limiting both maximum RF output power and human

exposure to RF radiation, the maximum antenna gain including cable loss in a mobile-only
exposure condition must not exceed the gain values presented in the table below:

 6.5 dBi in Cellular band

 3 dBi in PCS band

 6.0 dBi in LTE Band 4

 9.0 dBi in LTE Band 7

 9.0 dBi in LTE Band 13 (Note: LTE Band 13 is not permitted in Canada.)

4112476 Rev 0.4 March 20, 2013 58

Product Technical Specification

3. The AR7550 modem may transmit simultaneously with other collocated radio transmitters
within a host device, provided the following conditions are met:

 Each collocated radio transmitter has been certfied by FCC / IC for mobile application.
 At least 20 cm separation distance between the antennas of the collocated transmitters

and the user’s body must be maintained at all times.
 The output power and antenna gain must not exceed the limits and configurations

stipulated in the following table.

Device Technology Band

AR7550
Module

Collocated
transmitters

1. Valid collocated Transmitter combinations: WLAN+BT; WiMAX+BT.

(WLAN+WiMAX+BT is not permitted.)

LTE

UMTS

CDMA

WLAN

1

WiMAX

BT 2400-2500 15 5

4 1710-1755 24 6

7 2500 – 2570 24 9

13 777-787 24 6

2 1850-1910 24 3

5 824-849 24 3

BC0 824-849 25 3

BC1 1850-1910 25 3

2400-2500 29 5

5150-580 29 5

2300-2400 29 5

2500-2700 29 5

3300-3800 29 5

Frequency
(MHz)

Maximum
conducted power

Maximum antenna
gain

4. A label must be affixed to the outside of the end product into which the AirPrime AR7550
device is incorporated, with a statement similar to the following:

a.

This device contains FCC ID: N7NAR7550
This equipment contains equipment certified under IC: 2417C-AR7550

A user manual with the end product must clearly indicate the operating requirements and conditions
that must be observed to ensure compliance with current FCC/IC RF exposure guidelines.

The end product with an embedded AirPrime AR7550 device may also need to pass the FCC Part 15
unintentional emission testing requirements and be properly authorized.

Note: If this module is intended for use in a portable device, you are responsible for separate approval to

satisfy the SAR requirements of FCC Part 2.1093 and IC RSS-102.

41124764188 Rev 0.41 March 20, 2013 59

9. References

The table below lists the reference specifications for this product.

Table 67. Reference Specifications

Ref Title Issuer

Recommended Minimum Performance Standards for

[1]

cdma2000 High Rate Packet Data Access Terminal – C.S0033

Recommended Minimum Performance Standards for

[2]

cdma2000 Spread Spectrum Mobile Stations – C.S0011 (IS-98D)

[3] Universal Serial Bus Specification

Universal Serial Bus CDC Subclass Specification for Wireless Mobile

[4]

Communication Devices

[5] Universal Serial Bus Class Definitions for Communication Devices

[6] AirPrime AR Series Customer Process Guidelines Sierra Wireless

[7] AirPrime AR7 Series AT Command Interface Specification Sierra Wireless

[8] AirPrime AR7 Series Firmware Download Guide Sierra Wireless

3GPP2

3GPP2

USB Implementers
Forum

USB Implementers
Forum

USB Implementers
Forum

4112476 Rev 0.4 March 20, 2013 60

10. Abbreviations

The table below lists several abbreviations used in this document.

Table 68. Abbreviations

Abbreviation Description

CDMA Code Division Multiple Access

DRX Discontinuous Receive

GNSS Global Navigation Satellite System

GSM Global System for Mobile Communications

HSPA High Speed Packet Access

LTE Long Term Evolution

SCI Slot Cycle Index

USB Universal Serial Bus

WCDMA Wideband Code Division Multiple Access

WWAN Wireless Wide Area Network

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