Wireless Audio Systems, based on Avnera’s AV7211 IC
General Description
Every consumer wants to be free from wires, but system designers could never find a low-cost, high-quality, easy-to-use wireless audio solution for speakers, microphones, headphones and headsets on the market.
Avnera’s proprietary wireless system changes the game by taking a new approach to wireless audio. The wireless protocol was designed from the ground up and delivers uncompressed stereo audio over the air without interference problems.
Avnera’s wireless modules offer a low-touch, easy-to-integrate wireless audio solution and enable fast time to market by already solving the problem associated with FCC, antenna tuning and board optimization.
Modules based on Avnera’s AV72xx silicon(also known as AudioMagic 1.5G) providebreakthrough wireless audio functionality with point to multipoint transport of uncompressedstereo PCM audio data from a singleAVMD7211 sender and a total of up to threesimultaneous AVMD7212 listeners.
Applications
9Wireless audio transmitter for portable
audio player
9Wireless audio distribution hub for
surround speakers
Ordering Options
AVMD7211-04-ACNA: Analog-in, normalrange
AVMD7211-04-ACPA: Analog-in, extended range
Features
9Uncompressed audio, point to multipoint
capable (1 to 3)
9Audio path SNR: Stereo 84 dB SNR, 48 kHz
sampling rate
9Support for 14m (normal) and 30m
(extended) range
9Frequency range: 2.4 GHz ISM band,
continuous dynamic frequency selection
9Forward error correction coding, error
detection, and audio-specific error concealment
9Diversity antennas for multipath and fading
mitigation
9Connector: Edge contact via array supports
surface mount
9Auto-search/synch and dynamic channel
selection
9Low, fixed latency suitable for video lip-
synch
9Support for 16, 20, 24, and 32 bit PCM
words at 16, 22.05, 24, 32, 44.1, 48, and 96 kHz
9General purpose over-the-air (OTA) serial
interface:
92 kbps, bi-directional, full duplex 9Support for meta-data and remote
General Description______________________________________________________________1Applications_____________________________________________________________________1Ordering Options_________________________________________________________________1Features________________________________________________________________________11Table of Contents_____________________________________________________________22Lists of Figures and Tables_____________________________________________________33AVMD7211 Functional Block Diagrams__________________________________________44AVMD7211 Pin Information___________________________________________________65AVMD7211 Mechanical Dimensions_____________________________________________76Electrical Specifications_______________________________________________________8
6.1Absolute Maximum Ratings_____________________________________________________________8
9Ordering Information________________________________________________________1810Contact Information and Legal Disclaimer_____________________________________19
CONTENTS SUBJECT TO CHANGE WITHOUT NOTICE2AVNERA PROPRIETARY & CONFIDENTIAL
When paired with an AV7212-based companion receiving device, the AVMD7211 modules support group mode scenarios in which one sender can transmit audio to up to three listener modules simultaneously.
The nominal output power without PA is 0 dBm (normal range) and with a PA is +10 dBm (extended range)into the antennas.
Figure 1: AVMD7211 Module Block Diagram without RF Power Amplifier (normal range)
Figure 2: AVMD7211 Module Block Diagram with RF Power Amplifier (extended range)
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The AVMD7111’s SPI interface is used to allow an external host to control the AV7111 senderIC and to facilitate testing of the module.
The GPIO and LED lines allow buttons and LEDs to be connected to the AVMD7111 to allow the user to control the AudioMagic™ system and communicate the system’s state to the user.
These three pins form the module’s analog audio input. The COM pin is tied to analog groundon the module and should not be connected to ground in the host system.
This pin connects directly to the “PWR” pin on the AV7111 IC and is used to signal the module to power on and off.
These pins provide power to various elements of the AVMD7111. The V3.3 pin, connected to the AV7111 IC’s VBATT pin, supplies power to the AV7111. The VA pin supplies power to the ADC. On the PA-enabled version of the module, VCCPA supplies power to the RF power amplifier. In normal operation, all three pins are connected to the 3.3V (nom) main supply.
The VDDIO pin is connected to the VDDIO regulator bypass pin on the AV7111. The pin can be used to indicate when the AV7111 IC is powered on. Note that VDDIO must NOT be usedto power an external device, nor should it be driven by an external supply.
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1 VCCPA Analog Power RF power amplifier supply connection 2 AGND Ground Analog section ground 3 V3.3 Analog Power 3.3V power supply connection 4 AGND Ground Analog section ground 5 VA Analog Power ADC power supply (3.3 V) 6 AINL Analog InputLeft-channel audio input. 7 COM Analog InputAnalog common connection 8 AINR Analog InputRight-channel audio input
9 PWR Analog InputPower switch input 10 LED2 Digital Output LED drive line 11 LED1 Digital Output LED drive line 12 LED0 Digital Output LED drive line 13 NC NC NC 14 NC NC NC 15 NC NC NC 16 GPIO6 Digital I/O General-Purpose I/O 17 GPIO5 Digital I/O General-Purpose I/O 18 DGND Ground Digital section ground 19 VDDIO Digital Power 3.3V regulated voltage 20 GPIO4 Digital I/O General-Purpose I/O 21 GPIO3 Digital I/O General-Purpose I/O 22 GPIO2 Digital I/O General-Purpose I/O 23 GPIO1 Digital I/O General-Purpose I/O 24 SDO Digital Output SPI data output 25 SDI Digital Input SPI data input 26 SSB Digital Input SPI slave select, active low 27 SCLK Digital Input SPI data clock input 28 AGND Ground Analog section ground 29 AGND Ground Analog section ground 30 AGND Ground Analog section ground
CONTENTS SUBJECT TO CHANGE WITHOUT NOTICE6AVNERA PROPRIETARY & CONFIDENTIAL
Absolute Maximum Ratings (AMR) are stress ratings only. AMR corresponds to the maximum value that can be applied without leading to instantaneous or very short-term unrecoverable hard failure (destructive breakdown). Stresses beyond those listed under AMR maycause permanent damage to the device.
Functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Range” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may adversely affect device reliability.
Device functional operating limits and guaranteed performance specifications are given under Electrical Characteristics at the test conditions specified.
CONDITION MIN MAX
VA Supply Voltage Input -0.3V 6V V3.3 Supply Voltage Input-0.3V 4V VCCPA Supply Voltage Input 0 6V Input Voltage Range – Digital
Inputs Input Voltage Range – Analog
Inputs
-0.3V V
-0.3V V
Operating Temperature -40ºC +85ºC Storage Temperature -40ºC +100ºC
Static Discharge Voltage – HBM *
1000V
*Terminology: HBM => ESD human body model
VDDIO
A
+ 0.3V
+0.3V
6.2 Recommended Operating Range
PARAMETER MIN TYP MAX UNIT
VA pin voltage 3.0 3.5 V V3.3 pin voltage 3.0 3.5 V VCCPA pin voltage 3.0 3.6 V Ambient Temperature (TA) -20 70 ºC
CONTENTS SUBJECT TO CHANGE WITHOUT NOTICE8AVNERA PROPRIETARY & CONFIDENTIAL
The AVMD7211 module is designed to be surface mounted directly to a supporting system board. The antennas are tuned to the correct impedance and band center in the presence of the module circuit board, without any other close-by materials. As such, in the final application the module must be positioned in such a way that all foreign material, including other circuit boards, ground plane, other metal structures, and enclosure components, must be kept away from the antennas. The diagrams in the figures below provide guidance for mounting the module as well as configuring the system board in the vicinity of the module itself.
Figure 4: Main board ground plane guidelines in the vicinity of the module
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The schematic shown below represents a generic application, showing how the AVMD7212 would be connected to the outside world for the purposes of control, power supply, and analog output.
TBD
Figure 8: AVMD7211 application schematic
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Applications employing long signal lines to connect to the module are under increased risk of EMI. This can manifest as buzzing noise or spurious emissions impacting FCC certification. System designers should avoid:
•Long cables connecting the modules to headphones or speakers
•Long power cords connecting the modules to AC wall adapters
Adding ferrite chips close to the edge of the modulescan reduce the impact of signal coupling and sub-1GHz spurious emissions (see Figure below). This mitigation method may not be necessary when connecting the analog inputs directly to a circuitry located on the main board using short wires or PCB traces. Note that connecting the analog inputs directly to the outside world through a jack or other terminals re-introduces the risk of spurious emissions.
Figure 9: Example of sub-1GHz EMI suppression using in-line ferrite chips
The ferrite chips should be located close to the edge of the module.
Note: Do not connect analog input COM pin to external ground. The COM line is carefully connected to ground inside the module. Connecting COM to an external ground may create a ground loop that can lead to either or both unwanted noise pickup orradiation of spurious signals.
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8 FCC and Industry Canada certification information
8.1 Label Information
The AVMD7211 family of modules has passed the requirements set by the US Federal Communications Commission (Part 15) and Industry Canada (RSS-Gen, Issue 2, June 2006 and RSS-210e) for certification asmodular intentional radiators. The certification identification numbers are as follows:
US FCC ID: V3CAVMD7F11A Industry Canada (IC): 7853A-AVMD7F11A
Avnera makes the following representations: This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, (2) This device must accept any interference received, including
interference that may cause undesired operation.
Per FCC regulation 47 CFR 15.21: Changes or modifications not expressly approved by Avnera, as the party responsible for compliance, can void the user’s authority to operate the equipment using AVMD7211 modules.
8.2 Equipment labeling requirements
The statement shown below, or its equivalent, must appear on the external label of every piece of equipment that containsan AVMD7211 module. If the size of the final equipment is too small to support such a label, the statement described in must appear in the user manual for that equipment.
Contains FCC ID V3CAVMD7F11A
IC: 7853A-AVMD7F11A
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference (2) This device must accept any interference received,
including interference that may cause undesired operation
CONTENTS SUBJECT TO CHANGE WITHOUT NOTICE16AVNERA PROPRIETARY & CONFIDENTIAL
The statements shown below, or their equivalents, must appear in the user manual for equipment containingAVMD7211 modules:
Contains FCC ID V3CAVMD7F11A
IC: 7853A-AVMD7F11A
This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
(1) This device may not cause harmful interference (2) This device must accept any interference received,
including interference that may cause undesired operation
Per FCC regulation 47 CFR 15.21: Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.
CONTENTS SUBJECT TO CHANGE WITHOUT NOTICE17AVNERA PROPRIETARY & CONFIDENTIAL