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Reproduction in whole or in part is prohibited without the prior written permission of the copyright holder.
February 2007
Headset Reference Design
nRD24V1
User Guide v1.0
Revision 1.0 Page 2 of 25
User Guide
Liability disclaimer
Nordic Semiconductor ASA reserves the right to make changes without further notice to the product to
improve reliability , function or design. Nordic Semiconductor ASA does not assume any liability arising out
of the application or use of any product or circuits described herein.
Life support applications disclaimer
These products are not designed for use in life support appliances, devices, or systems where malfunction
of these products can reasonably be expected to result in personal injury. Nordic Semiconductor ASA customers using or selling these products for use in such applications d o so at their own risk and agr ee to fully
indemnify Nordic Semiconductor ASA for any damages resulting from such improper use or sale.
Contact details
For your nearest dealer, please see http://www.nordicsemi.no
Receive available updates automatically by subscribing to eNews from our homepage or check our web-
site regularly for any available updates.
Main office:
Otto Nielsen’s vei 12
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Phone: +47 72 89 89 00
Fax: +47 72 89 89 89
www.nordicsemi.no
Revision History
Date Version Description
February 2007 1.0
Revision 1.0 Page 3 of 25
Headset Reference Design v1.0
Contents
1 Introduction .................................................................................................4
2 System Description.....................................................................................5
3 Hardware description..................................................................................7
3.1 nRD24V1 Radio module ......................................................................7
3.1.1 Audio Codec.....................................................................................7
3.1.2 Micro controller.................................................................................8
3.1.3 Radio circuit .....................................................................................8
3.1.4 Antenna matching network...............................................................8
3.1.5 Power supply....................................................................................8
3.1.6 Programming....................................................................................8
3.1.7 Specifications...................................................................................9
3.2 Application board .................................................................................10
3.2.1 Audio interface.................................................................................10
3.2.2 Jumpers ...........................................................................................12
3.2.3 Antenna............................................................................................12
3.2.4 Power supply....................................................................................12
3.2.5 Buttons.............................................................................................13
3.2.6 Programming....................................................................................13
3.3 USB dongle..........................................................................................14
3.3.1 USB Interface...................................................................................15
3.3.2 Micro controller.................................................................................15
3.3.3 Radio circuit .....................................................................................15
3.3.4 Power supply....................................................................................15
3.3.5 Programming....................................................................................15
3.3.6 Specifications...................................................................................16
4 Hardware design guidelines........................................................................17
4.1 Headset................................................................................................17
4.1.1 Antenna............................................................................................17
4.1.2 Interfaces .........................................................................................17
4.1.3 Crystals............................................................................................18
4.1.4 MCU.................................................................................................18
4.1.5 Battery..............................................................................................18
4.2 USB dongle..........................................................................................19
4.2.1 Antenna............................................................................................19
4.2.2 MCU.................................................................................................19
4.2.3 Crystals............................................................................................19
5 Appendix.....................................................................................................20
5.1 Bill Of Materials (BOM) ........................................................................20
5.2 Application board schematics ..............................................................23
5.3 RF module schematics.........................................................................24
5.4 USB dongle schematics.......................................................................25
Revision 1.0 Page 4 of 25
User Guide
1 Introduction
This user guide is for the nRD24V1 headset reference design, a voice quality wireless headset for Voice
over IP (VoIP) applications. The quality of the audio in this design is the same as the audio quality in telephony.
This user guide describes the nRD24V1 system, HW modules and give s gu idelines on how to t ake th is re ference design and build it into a headset application for a finished product.
The nRD24V1 consists of a USB dongle and two application boards with a radio modu le mounted. You can
establish a full duplex voice link between one application board and the USB dongle or between the two
application boards.
Target applications for the nRD24V1 are:
• Voice over IP headsets
• Short range intercom applications
•Toys
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Headset Reference Design v1.0
2 System Description
The headset unit can be used to communicate with either a USB dongle or an audio dongle.
Note: The audio dongle is simply a headset unit with different firm ware and jumper settings.
Figure 1. ”Headset unit with a USB confi guration” and Figur e 2. ”System d iagram of headset unit with USB
configuration” illustrate the headset unit with a USB configuration.
Figure 1. Headset unit with a USB configuration
Figure 2. System diagram of headset unit with USB configuration
Figure 3. ”Headset unit with an audio dongle configuration” and Fi gure 4. ”Syste m diagram of headset unit
with audio dongle configuration” illustrate the headset unit with audio dongle configuration.
Figure 3. Headset unit with an audio dongle configuration
USB
dongle
Headset
unit
DAC
ADC
MCU
Voice
Protocol
I/O
I/O
PHY
RF
ShockBurst
Buttons LED
Application
Audio
Out
Audio
In
Application
MCU
Voice
Protocol
I/O
I/O
PHY
RF
ShockBurst
LED
I/O
USB
Audio Controller
USB
USB
In/Out
Audio
dongle
Headset
unit
Revision 1.0 Page 6 of 25
User Guide
Figure 4. System diagram of headset unit with audio dongle configuration
The headset unit and the audio dongle are based on the same hardware. Both use an audio codec to provide coding and decoding of the analog audio signals to 16-bit linear PCM code. This bit stream is processed by the micro controller to an 8-bit a-law bit stream, which is sent to the nRF24L01 for wireless
transmission. The nRF24L01 uses the ShockBurst feature to transm it and rece ive the RF packe ts in a time
multiplexed scheme. The micro controller fetches received 8-bit a-law samples from the nRF24L01, converts to 16-bit linear PCM, and outputs to the audio codec. Button status is read by the MCU and embedded in the RF packets.
The USB Dongle uses a USB Audio Controller to handle the USB interface. The audio samples are 16 bit
linear PCM between the USB Audio Controller and the micro controller, where the micro controller acts as
a bus master. The audio frame signals are derived from clock output from the USB Audio Controller to
keep the audio frames in sync with the USB audio frames. The micro controller can also access the USB
HID interface through the I2C bus, also with the micro controller as the bus master. The USB HID interface
is used to upstream button status received fro m the headset to the USB host. The m icro controller convert s
the 16 bit linear PCM code to an 8-bit a-law bit stream, which is sent to the nRF24L01 for wireless transmission. The nRF24L01 uses the ShockBurst feature to transmit and receive the RF packets in a time multiplexed scheme.
DAC
ADC
MCU
Voice
Protocol
I/O
I/O
PHY
RF
ShockBurst
ButtonsLED
Application
Audio
Out
Audio
In
DAC
ADC
MCU
Voice
Protocol
I/O
I/O
PHY
RF
ShockBurst
Buttons LED
Application
Audio
Out
Audio
In
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Headset Reference Design v1.0
3 Hardware description
3.1 nRD24V1 Radio module
The radio module is a complete system for telephone quality wireless headset applications intended for
VoIP. It can be used in a headset, or in an audio module for connection to a PC audio outlet. There are 6
GPIOs for buttons or LEDs on the radio module.
The radio module is mounted on a 25 x 12 x 0.8 mm, 4-layer FR4 circuit board, with components on one
side.
Figure 5. nRD24V1 radio module
3.1.1 Audio Codec
The audio codec is a XE3005 from Semtech that receives a 4.096 MHz master clock from the micro controller. The micro controller configures the codec through the SPI interface. The 8 ksps audio samples are
transferred on the I2S interface, where the micro controller is the bus master.
The microphone input has a 1.1 VDC bias for driving the microphone.
The loudspeaker outputs are a differential class D output and need some external filtering components.
1 RF crystal 4 Audio codec
2 nRF24L01 5 MCU crystal
3MCU
1
2
3
5
4
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3.1.2 Micro controller
The micro controller is an AVR, ATmega88 and runs on a 4.096 MHz crystal. The micro controller’s main
tasks are:
• Setting up codec and RF circuits.
• Converting 16 bit PCB audio samples from the codec to 8 bit a-law samples to the radio circuit.
• Converting 8-bit a-law samples from the radio circuit to 16-bit linear PCM.
• Handling the RF protocol.
Additionally , five bu tton inputs a re scanned and one output is provided for driving. For example, this can be
used for an LED.
3.1.3 Radio circuit
The radio circuit (nRF24L01) is a complete radio transceiver for use in the unlicensed 2.4 GHz band. A 16
MHz crystal is used as a frequency reference for the RF. The RF output is matched to approximately 50
ohm at the antenna port. See section 3.1.4 ”Antenna matching network” below.
3.1.4 Antenna matching network
The RF output of the radio module is matched to approximately 50 ohm. An antenna is needed to set up
the RF link. There is a variety of dif ferent a ntenna ty pe s, please see section 4.1.1 ”Anten na” for mor e information.
3.1.5 Power supply
The module needs a power supply in the range of 1.9 to 3.3 Volt s. The module has be en tested with a supply consisting of two ZinkAir cells (type 675) in series. Check the current consumption values shown in
Table 1. ”Electrical Specifications” below.
Note: Not all battery types are capable of handling the peak and average currents, even if the bat-
tery capacity is sufficient.
3.1.6 Programming
The module can be programmed using the ISP connector on the application board (see section 3.2 ”Application board”), by connecting the appropriate pins on the module, or by using test probes on the corresponding exposed vias on the back of the board.
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3.1.7 Specifications
Table 1. Electrical Specifications
Table 2. Physical Specifications
Operating conditions Status Value
Supply voltage 1.9 - 3.6 V
Current consumption Idle < 1 mA average (15 mA peak) at 2.5 V supply
Connected < 7 mA average (15 mA peak) at 2.5 V supply
Radio frequency 2402-2478 MHz
Output power 0 dBm
PCB attributes Description
PCB type 0.8 mm 4 layer FR4
PCB dimension (length x width x height) 25 mm x 12 mm x 0.8 mm
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3.2 Application board
The nRF24L01-VHR1 application board contains all peripherals necessary to build a complete audio module from the nRF24L01-VHR1 radio module.
Figure 6. Application board components
3.2.1 Audio interface
This module can be used to set up a wireless audio link, for example, from a PC to a headset. The radio
module is the same for both sides of the link, but needs some external component s to interface with either
the PC audio connections, or a microphone/loudspeaker for a headset.
1 Radio module 7 P3 external power
2 Linear regulator 8 Batteries
3 Jumpers 9 Switches 7 and 8
4 Audio interface 10 ISP programming
5 Jumpers 11 Buttons
6Switch 6
4
5
7
8
10
11
3
1
2
6
9
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Headset Reference Design v1.0
3.2.1.1 Headset interface
The loudspeaker(s) are driven differentially, and need some filtering due to the class D output amplifier of
the audio codec. Figure 7. ”Loudspeaker interface” shows a typical filter network that can be used for driving a headset loudspeaker. The filter depends on the chosen loudspeaker.
The microphone can be connected directly to the codec input. The codec input has a 1.1 V supply that can
power a typical headset microphone.
Figure 7. Loudspeaker interface
3.2.1.2 PC interface
The differential loudspeaker output from the codec must be co nnected single ended to the PC microphone
input and the PC loudspeaker output must be connected to the codec microphone input to interface with a
PC audio port. Figure 8. ”PC input interface” show s the networks that a ccommodate this. The loudspeaker
output from the PC must be level adjusted and a network as shown in Figure 9. ”PC ou tput interface ” used.
Figure 8. PC input interface
L2
470u
C4
100p
C1
100p
R1
56
R2
56
C2
4.7u
C3
4.7u
L1
470u
AOUTP
AOUTN
R7
4.7k
R8
4.7k
C8
2.2u
C9
2.2u
C5
10n
C7
100n
R9
22k
R4
22k
R6
22k
R5
22k
C6
10u
+
-
V-
V+
U1
LM7301
3
4
1
2
5
R3
1k
PC microphone input
L2
470u
C4
100p
C1
100p
R1
56
R2
56
C2
4.7u
C3
4.7u
L1
470u
AOUTP
AOUTN
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Figure 9. PC output interface
3.2.2 Jumpers
The application board can be set up to interface a headset microphone and loudspeaker, or a PC audio
outlet by placing the jumpers as shown in Table 3. ”Audio filter settings” below. The filter components
mounted should be appropriate for most headset loudspeakers.
Table 3. Audio filter settings
3.2.3 Antenna
The RF output of the radio module is matched to approximately 50 ohm. An an tenna must be connected to
the SMA connector to set up an RF link.
3.2.4 Power supply
The application board is fitted with two coin-cell battery holders, connected in series, for use with ZinkAir
(type 675) batteries. The board also contains a footprint for a CR2 Li battery holder (1/2 AA, Bulgin
BX0031). Alternatively, an external power supply can be connected to P3. You select battery or external
voltage with SW6.
The voltage supply to the RF module should be between 1.9 and 3.6 V. If the onboard 2.5 V linear regulator is used, the input voltage should be between 3 and 15 V. The linear regulator can be switched on or
bypassed with SW7 and SW8 (both switches should have the same position).
Note: Do not exceed 3.6 V when using external voltage unless the linear regulator is used, as this
can damage the radio module.
CJ2 CJ3 W1 W2
Connecting to
headset
Connect to headset
microphone.
Connect to headset
loudspeaker
Mount jumpers 4
and 5
Mount jumper 2.
Connecting to PC Connect to PC micro-
phone input
Connect to PC loudspeaker output
Mount jumpers 1,
2 and 3
Mount jumper 1.
R1
1k
R2
47
C1
2.2u
C2
2.2u
PC loudspeaker out AIN
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3.2.5 Buttons
There are five buttons on the application board and these are co nnected to the AVR micro controller on the
radio module as shown in Figure 10. ”Button mapping”.
Figure 10. Button mapping
3.2.6 Programming
The radio module can be programmed through the 6-pin ISP connector (P1) with an AVR programming
tool like the STK500 from Atmel. The programming procedure is as follows:
1. If the unit has never been programmed, set the AVR fuses:
• Preserve EEPROM memory through chip erase cycle; [EESAVE = 0]
• Brown-out detection level at Vcc=1.8V; [BODLEVEL=110]
• Clock output on PORTB0; [CKOUT=0]
• Ext.Crystal Osc. Frequency 3.0 - 8.0MHz; [CKSEL=1101 SUT=11]
2. Write the SW hex file into the AVR program memory.
3. Write a 3-byte ID into the AVR EEprom. The address should be written with the MSB at address
00.
SW1
AVR pin 23
SW2
AVR pin 24
SW3
AVR pin 25
SW4
AVR pin 26
SW2
AVR pin 27
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3.3 USB dongle
The USB dongle establishes a wireless audio link with the radio module in a headset and is identified as an
audio device in the PC operating system.
The USB dongle is mounted on a 0.8 mm, 4-layer FR4 circuit board, with components on both sides of the
board.
Figure 11. nRD24V1 USB dongle top side
Figure 12. nRD24V1 USB dongle bottom side
1 MCU 3 nRF24L01
2 MCU crystal 4 RF crystal
1 USB MCU 3 ISP connector
2 EE Prom
1
2
3
4
1
3
2
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3.3.1 USB Interface
The USB interface is handled by the Sonix SN11220 USB Audio Controller. All the USB communications
are handled by the SN11220. The audio samples are 16 bit linear PCM on the I2S port, where the micro
controller acts as a bus master (PADFUN mode 4’1100 in the SN11220ACF data sheet). The audio frame
signals are derived from the 2.048 MHz clock output from the USB controller. This synchronizes the audio
frames with the USB audio frames. The micro controller can also access the USB HID interface through
the I2C bus, also with the micro controller as the bus master.
3.3.2 Micro controller
The micro controller is an AVR, ATmega88 that runs on a 6.00 MHz crystal. The micro controller’s main
tasks are:
• Setting up USB controller and radio circuits.
• Converting 16 bit PCM audio samples from the USB controller to 8 bit a-law samples for the radio
circuit.
• Converting 8-bit a-law samples from the radio circuit to 16-bit linear PCM.
• Handling the RF protocol.
• Optional HID interface for communication with PC application.
In addition, an LED output is available. The LED will light up when USB audio activity is present on the
USB port.
3.3.3 Radio circuit
The radio circuit (nRF24L01) is a complete radio transceiver for use in the unlicensed 2.4 GHz band. A 16
MHz crystal is used as frequency reference for the RF and an antenna is included in the layout.
3.3.4 Power supply
The USB dongle is powered from the USB port and needs no extra supply.
3.3.5 Programming
A 6-pin ISP connector is available on the back of the PCB. The included ISP cable can be used to connect
this connector to an AVR programming tool like the STK500 from Atmel.The programming procedure is as
follows:
1. If the unit has never been programmed, set the AVR fuses:
• Preserve EEPROM memory through chip erase cycle; [EESAVE = 0]
• Brown-out detection level at Vcc=2.7V; [BODLEVEL=101]
• Ext. Full-swing Crystal; [CKSEL=0111 SUT=01]
2. Write the SW hex file into the AVR program memory.
3. Write a 3-byte ID into the AVR EEprom. The address should be written with the MSB at address
00.
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3.3.6 Specifications
Table 4. Electrical Specifications
Table 5. Physical Specifications
Operating conditions Status Value
Supply voltage 4.5 - 5.5 V
Current consumption Idle < 24 mA
Connected < 28 mA
Radio frequency 2402-2478 MHz
Output power 0 dBm
PCB attributes Description
PCB type 0.8mm 4 layer FR4
PCB dimension (length x width x height) 42mm x 16mm x 0.8mm
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4 Hardware design guidelines
This chapter describes important issues that might affect you when developing the headset refere nce
design for a finished product. The USB dongle can be used as-is, but the headset must be redesigned to fit
into a headset for a finished product. However, the radio module mounted on the headset can be used asis together with the audio interfaces from the application board.
Note: Most radio regulations do not allow more than 0dBm output power without doing proper fre-
quency hopping. Adding a PA to this design requires a major re-design of the radio protocol
because the headset reference design uses a frequency agility protocol.
4.1 Headset
The radio module is used as-is in the headset design, but it must be interfaced in a way that en sures optimal performance.
4.1.1 Antenna
The radio module is connected to the antenna on the application board. This antenna does not fit into a
headset design for a finished product, so using th e ra dio mo du le in a he ad se t ap plic at ion for a finish ed
product will require a different type of antenna.
In a headset application for a finished product, the radio module must be mounted on a PCB with an
antenna terminal. On this antenna terminal, any 50 ohm 2.4GHz antenna can be used, from an inexpensive PCB antenna to space saving chip antennas.
There are different types of PCB antennas, fro m inverted F antennas to simple quarter wave antennas.
You must know the characteristics of the chosen antenna and implement it as required. Tuning the
antenna will be necessary because an antennas impedance and performance is affected by the environment the antenna is used in.
Using a chip antenna must only be done according to the chip antenna vendors recommendations.
The radio module is equipped with the recomm ended ant enna matching ne twork layout fo r the nRF24L01.
When operating from the application board, the radio module’s antenna matching network is tuned to
match the application board antenna impedance.
When using the radio module in a headset applicat ion for a fin ish ed pro du ct it is impor tant to tune the
antenna matching network to match the impedance at the antenna’s terminal. Another important task of
the antenna matching network is to suppress spurious energy. You can achieve this by following our white
paper called “Tuning_the_nFR24xx_matching_network” available on our website www.nordicsemi.no.
4.1.2 Interfaces
4.1.2.1 Buttons
Any active closed push buttons referring to ground can be used because the MCU used on the radio module has internal pull-up resistors on the button input signals. The radio module can handle up to five bu ttons.
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4.1.2.2 Audio interface
The audio interfaces from the application board should be used when using the radio module as-is in a
design. The audio interfaces are matched to the used audio codec on the radio module. Using a different
codec or load on the interfaces requires redesign of the audio interfaces.
4.1.3 Crystals
The crystal used as the RF crystal is a 16 MHz crystal. Any replacement of this crystal must fulfill the crystal requirements found in the nRF24L01 Product Specification.
The MCU crystal fulfills the requirements given by the MCU. The frequency must be 4.096MHz in order to
get the timing correct. Any replacements must follow these requirements.
4.1.4 MCU
It is important that the MCU has a double buffered SPI in both the TX and RX direction because the MCU
handles the audio stream and requires it to be continuous.
A replacement of the MCU must fulfill these requirements:
• 8-bit MCU
• 4.096 MHz clock frequency
• 1 to 2 cycles per instruction
• 4bytes E2PROM Memory (can be external)
• 1kbyte of IRAM (can maybe work with 512kbytes)
• 8kbyte program memory (possible to get down to 5 to 6kbytes)
• One Double buffered, synchronous hardware SPI both on RX and TX -or- Ideally I2S interface
• One SPI port for RF and codec
• Watchdog times for power mana gement
• One 16-bit timer (Master sync clock)
• One 8-bit timer (hardware sync clock)
• 1.9 to 3.6V supply voltage
4.1.5 Battery
The batteries included in the reference design kit are of the type Zink-Air (Zn), size 675. Two batteries of
this size are connected in series to achieve the supply voltage needed.
Any battery that can supply a voltage be tween 1.9V and 3.6V a nd sust ain the peak cu rrent of 15mA can be
used in this application.
You can calculate the battery lifetime in both “talk time” and “standby time” from the average current consumption. At Vdd=3V the average current con su m pt ion in connect mode is 7mA and the average current
consumption in idle mode is 250µA. (At Vdd=2V they are 5.7V and 230µA, respectively.) A battery with
capacity 630mAh, like the Zn 675, will have the following battery lifetime:
• Talk time: 630mAh/7mA = 90h.
• Standby time: 630mAh/250µA=2520h.
The figures for Vdd=3V are used because the two batteries in series have a nominal output voltage of
2.8V.
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4.2 USB dongle
4.2.1 Antenna
The USB Dongle uses a PCB quarter wave antenna. The USB Dongle is production ready, and any modifications to the antenna are only required as part of the antenna tuning process to compensate for plastic
housing, and so on.
If you want an antenna redesign, any 50 ohm 2.4GHz antenna can be used, from an inexpensive PCB
antenna to space saving chip antennas.
There are different types of PCB antennas, fro m inverted F antennas to simple quarter wave antennas.
You must know the characteristics of the chosen antenna and implement it as required. Tuning the
antenna will be necessary because an antenna’s impedance and performance are affected by the environment the antenna is used in.
Using a chip antenna must only be done according to the chip antenna vendors recommendations.
The USB Dongle is equipped with the recommended antenna matching network layout for the nRF24L01
and a PCB quarter wave antenna. If a different antenna is going to be used it is important to tune the
antenna matching network to match the impedance at the antenna’s terminal. Another important task of
the antenna matching network is to suppress spurious ene rgy. This can be achieved by following our White
Paper named “Tuning_the_nFR24xx_matching_network” available on our website www.nordicsemi.no
4.2.2 MCU
A replacement of the MCU must fulfill these requirements:
• 8-bit MCU
• 6 MHz clock frequency
• 1 to 2 cycles per instruction
• 4bytes E2PROM Memory (can be external)
• 1kbyte of IRAM (can maybe work with 512kbytes)
• 8kbyte program memory (possible to get down to 5 to 6kbytes)
• One Double buffered, synchronous hardware SPI both on RX and TX -or- Ideally I2S interface
• One SPI port for RF and codec
• One two wire interface to USB Audio Controller for call control (open drain type)
• Watchdog times for power mana gement
• One 16-bit timer (Master sync clock)
• One 8-bit timer (hardware sync clock)
• 1.9 to 3.6V supply voltage
4.2.3 Crystals
The crystal used as the RF crystal is a 16 MHz crystal. Any replacement of this crystal must fulfill the crystal requirements found in the nRF24L01 Product Specification.
The MCU crystal fulfills the requirements given by the MCU. The frequency must be 6.0 MHz in order to
get the timing correct. Any replacements must follow these requirements.
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5 Appendix
5.1 Bill Of Materials (BOM)
Table 6. Application board BOM
Part Designator Footprint Description
10u C1 C3 C22 C27 SM/0805 Capacitor 0805/X5R/6V3/15%
10n C2 C4 C23 SM/0603 Capacitor 0603/X7R/50V/10%
4.7u C11 C14 SM/0603 Capacitor 0603/X5R/6.3V/10%
100p C16 C17 SM/0603 Capacitor 0603/NP0/50V/5%
2.2u C20 C21 C25 C26 SM/0603 Capacitor 0603/X5R/6.3V/10%
100n C24 SM/0603 Capacitor 0603/X7R/16V/10%
SMA CJ1 TH/SMA Coax connector 85 SMA-50-0-
101
3.5mm CJ2 CJ3 TH/CON/KLBR4 Audio Jack, 3.5mm KLBR 4
R D1 0603_D LED, Red EL19-21VRC
470u L1 L5 SM/1210 Inductor, Power
LQH32MN471J23L
6PIN2ROW P1 6PIN/2ROW Pin row 825457-3
PH2 P3 PHOENIX/2.54/2P Connector, screw MPT0.5/2-2.54
nRF24L01 VoIP Appli-
cation Board
PCB1 PCB
BC847BL Q1 SM/SOT23 NPN BC847BL
470 R3 SM/0603 Resistor, 0.1W 0603/1%
100k R4 R5 SM/0603 Resistor, 0.1W 0603/1%
56 R6 R7 SM/0603 Resistor, 0.1W 0603/1%
0 R8 R9 R12 SM/0603 Resistor, 0.1W 0603/1%
1k R13 R16 R17 R18
R25
SM/0603 Resistor, 0.1W 0603/1%
47 R14 SM/0603 Resistor, 0.1W 0603/1%
220 R15 SM/0603 Resistor, 0.1W 0603/1%
22k R19 R20 R21 R24 SM/0603 Resistor, 0.1W 0603/1%
4.7k R22 R23 SM/0603 Resistor, 0.1W 0603/1%
SW6x6 SW1 SW2 SW3 SW4
SW5
SM/SW/6x6 Switch, TACT B3S1000
SPDT SW6 SW7 SW8 TH/SW/OS1020 Switch, Mechanical
OS102011MS2QN1
nRF24L01-VHR1-RM U1 WHS-nRF24L01 Radio Module nRF24L01-VHR1-
RM
LP2985AIM5-2.5 U2 SM/SOT23-5 Linear Regulator LP2985AIM5-
2.5
12MM U3 U5 BAT/12MM Battery holder 12 mm 501
LM7301 U6 SM/SOT23-5 OpAmp LM7301IM5
5LUS W1 10PIN/2ROW/LUS Pin Row 825457-5
2LUS W2 4PIN/2ROW/LUS Pin row 825457-2
Jumper 2.54 mm WJ1 WJ2 WJ3 WJ4 Jumper, 2.54mm M7565-05
One in each corner
under the board
Rubber Feet
Revision 1.0 Page 21 of 25
Headset Reference Design v1.0
Table 7. USB dongle BOM
Part Designator Footprint Description
10n C1 C3 C4 C5 C6 C11 SM/0402 Capacitor 0402/X7R/16V/10%
10u C2 C13 C22 SM/0805 Capacitor 0805/X5R/6V3/15%
1.0n C7 SM/0402 Capacitor 0402/X7R/50V/10%
33n C8 SM/0402 Capacitor 0402/X7R/16V/10%
4.7p C9 SM/0402 Capacitor 0402/NP0/50V/5%
2.2n C10 SM/0402 Capacitor 0402/X7R/50V/10%
4.7p C12 SM/0402 Capacitor 0402/NP0/50V/5%
1.0p C14 C26 SM/0402 Capacitor 0402/NP0/50V/5%
15p C15 C16 SM/0402 Capacitor 0402/NP0/50V/5%
22p C17 C18 SM/0402 Capacitor 0402/NP0/50V/5%
47u C23 CAPMP3528X210L Capacitor,Tant, B
TAJB476K004R
470n C24 SM/0402 Capacitor 0402/X5R/6.3V/10%
2.2u C25 SM/0603 Capacitor 0603/X5R/6.3V/10%
G D1 060 3_ D LED, Green EL19-21UGC
4.7n L1 SM/0402 Inductor, RF
LQP15MN4N7B02D
8.2n L2 SM/0402 Inductor, RF
LQP15MN8N2B02D
5.6n L3 SM/0402 Inductor, RF
LQP15MN5N6B02D
USB-A P1 CON/USB-A/PLUG USB connector 48037-2100
nRF24L01 VoIP USB
Dongle Board
PCB1 PCB
PDTC115TU Q1 SM/SOT323 NPN with resistors
PDTC115TU
22k R1 SM/0402 Resistor, 0.1W 0402/1%
22 R2 R3 SM/0402 Resistor, 0.1W 0402/1%
1M R4 SM/0402 Resistor, 0.1W 0402/1%
100K R5 SM/0402 Resistor, 0.1W 0402/1%
0 R8 R9 R21 R26 SM/0402 Resistor, 0.1W 0402/1%
10 R10 SM/0402 Resistor, 0.1W 040 2/1%
2.2k R11 SM/0402 Resistor, 0.1W 0402/1%
3.3k R12 SM/0402 Resistor, 0.1W 0402/1%
470 R20 SM/0402 Resistor, 0.1W 0402/1%
10k R23 R24 SM/0402 Resistor, 0.1W 0402/1%
1.5k R25 SM/0402 Resistor, 0.1W 0402/1%
SN11220ACF U1 TSQFP50P900X900X16
0-48L
USB Audio Controller
SN11220ACF
nRF24L01 U2 QFN20-4x4 RF Transceiver nRF24L01
ATMega88 U3
QFN50P500X500X10033AL
Microcontroller ATmega88V10MU
93C46 U4
TSSOP-8
EEPROM, 1k AT93C46-10TU-
2.7
16MHz Y1
XW4*2.5
Crystal TSX-10 16MHz
6.0MHz Y2
TH/XO/CA-301
Crystal CA-301 6.000M-C
Connector P3 0 ISP Connector BM06B-SRSS-
TB(LF)(SN)
Revision 1.0 Page 22 of 25
User Guide
Table 8. Radio module BOM
Part Designator Footprint Description
100n C1 C13 SM/0402 Capacitor 0402/X7R/16V/10 %
22p C2 C5 SM/0402 Capacitor 0402/NP0/50V/5%
15p C3 C4 SM/0402 Capacitor 0402/NP0/50V/5%
4.7p C6 SM/0402 Capacitor 0402/NP0/50V/5%
2.2n C7 SM/0402 Capacitor 0402/X7R/50V/10%
1.0p C9 SM/0402 Capacitor 0402/NP0/50V/5%
10n C10 C14 C16 SM/0402 Capacitor 0402/X7R/16V/10%
1u C11 C12 SM/0402 Capacitor 0402/X5R/6.3V/10%
33n C15 SM/0402 Capacitor 0402/X7R/16V/10%
1.0n C17 SM/0402 Capacitor 0402/X7R/50V/10%
0.8p C18 SM/0402 Capacitor 0402/NP0/50V/5%
4.7n L1 SM/0402 Inductor, RF LQP15MN4N7B02D
8.2n L2 SM/0402 Inductor, RF LQP15MN8N2B02D
4.7n L3 SM/0402 Inductor, RF LQP15MN4N7B02D
nRF24L01 VoIP
RF Module Board
PCB1 PCB
10 R1 R3 SM/0402 Resistor, 0.1W 0402/1%
100k R2 R9 SM/0402 Resisto r, 0.1W 0402/1%
1M R4 SM/0402 Resistor, 0.1W 0402/1%
390k R5 SM/0402 Resistor, 0.1W 0402/1%
22k R8 SM/0402 Resistor, 0.1W 0402/1%
XE3005 U1 TSSOP-20 Audio Codec XE3005I033TRLF
ATMega88 U3 QFN50P500X500X
100-33AL
Microcontroller ATmega88V10MU
nRF24L01 U4 QFN20-4X4 RF Transceiver nRF24L01
4.096MHz Y1 TH/XO/CA-301 Crystal CSA309-4.096MABJ-UB
16MHz Y2 XW4*2.5 Crystal TSX-10 16MHz
Revision 1.0 Page 23 of 25
Headset Reference Design v1.0
5.2 Application board schematics
Revision 1.0 Page 24 of 25
User Guide
5.3 RF module schematics
KBD4
LED
-RESET
KBD0
KBD1
KBD2
KBD3
MOSI
MISO
SCK
AIN
AOUTP
AOUTN
VB
VB
VB
VB
VB
VB
VB
VB
Title
Size Document Number Rev
Date: Sheet
of
SCH-nRF24L01-VHR1-RM 4.0
RFmodule
A4
11Thursday, November 09, 2006
Schematic
Title
Size Document Number Rev
Date: Sheet
of
SCH-nRF24L01-VHR1-RM 4.0
RFmodule
A4
11Thursday, November 09, 2006
Schematic
Title
Size Document Number Rev
Date: Sheet
of
SCH-nRF24L01-VHR1-RM 4.0
RFmodule
A4
11Thursday, November 09, 2006
Schematic
CP13CP13
R2
100kR2100k
Y1
4.096MHzY14.096MHz
CP16CP16
C111uC11
1u
CP1CP1
C2
22pC222p
CP9CP9
L3
3.9nL33.9n
C9
1.5pC91.5p
CP4CP4
R110R1
10
CP6CP6
C13
100n
C13
100n
R8
22kR822k
CP2CP2
R6
DNMR6DNM
C15
33n
C15
33n
CP8CP8
L1
2.7nL12.7n
C18
1.0p
C18
1.0p
PCB1 nRF24L01 VoIP RF Module BoardPCB1 nRF24L01 VoIP RF Module Board
R7
DNMR7DNM
R310R3
10
U4
nRF24L01U4nRF24L01
ANT1
12
ANT2
13
IREF
16
VDDPA
11
VDD
18
VDD
7
VDD
15
DVDD
19
VSS
14
VSS
20
VSS
17
VSS
8
XC110XC2
9
CE1IRQ6CSN
2
SCK3MOSI4MISO
5
CP12CP12
U3
ATMega88U3ATMega88
PD0/RXD
30
PD1/TXD
31
PD2/INT0
32
PD3/INT1
1
PD4/XCK
2
PD59PD610PD7
11
PB0/CLKO
12
PB1
13
PB2/-SS
14
PB3/MOSI
15
PB4/MISO
16
PB5/SCK
17
PB6/XTAL17PB7/XTAL2
8
PC023PC124PC225PC3
26
PC4/SDA
27
PC5/SCL
28
PC6/-RESET
29
AVCC
18
VCC
4
VCC
6
GND
3
GND
5
GND
21
AREF
20
ADC619ADC7
22
GND
33
Y2
16MHzY216MHz
CP15CP15
CP10CP10
C7
2.2nC72.2n
CP18CP18
C10
10n
C10
10n
U1
XE3005U1XE3005
MCLK
1
MOSI
20
SS
2
SCK
19
SDI
18
SDO
17
BCLK
16
FSYNC
15
AOUTP14AOUTN12VDDPA
13
VSSPA11VREG119VREG165VREF6AIN
10
VDD
3
VSSD
8
VSSA
7
NRESET
4
L2
8.2nL28.2n
CP14CP14
CP5CP5
C3
15pC315p
CP7CP7
C17
1.0n
C17
1.0n
C5
22pC522p
R9
100kR9100k
CP11CP11
C6
4.7pC64.7p
R5
390kR5390k
R41MR4
1M
C4
15pC415p
C1
100nC1100n
C16
10n
C16
10n
C14
10n
C14
10n
CP17CP17
C121uC12
1u
CP3CP3
Revision 1.0 Page 25 of 25
Headset Reference Design v1.0
5.4 USB dongle schematics
-RESET
SCK
-RESET
MOSI
MISO
3V3
3V3
3V3
3V3
VUSB
VUSB
3V3
3V3
3V3
3V3
3V3
3V3
3V3
3V3
Title
Size Document Number Rev
Date: Sheet
of
SCH-nRF24L01-VHR1-UD 4.0
USB Dongle
A4
11Thursday, November 23, 2006
SCHEMATIC1
Title
Size Document Number Rev
Date: Sheet
of
SCH-nRF24L01-VHR1-UD 4.0
USB Dongle
A4
11Thursday, November 23, 2006
SCHEMATIC1
Title
Size Document Number Rev
Date: Sheet
of
SCH-nRF24L01-VHR1-UD 4.0
USB Dongle
A4
11Thursday, November 23, 2006
SCHEMATIC1
D1GD1
G
C17
22p
C17
22p
R222R2
22
U3
ATMega88U3ATMega88
PD0/RXD30PD1/TXD
31
PD2/INT0
32
PD3/INT1
1
PD4/XCK2PD59PD610PD7
11
PB0/CLKO
12
PB1
13
PB2/-SS
14
PB3/MOSI
15
PB4/MISO
16
PB5/SCK
17
PB6/XTAL17PB7/XTAL2
8
PC023PC124PC225PC3
26
PC4/SDA
27
PC5/SCL
28
PC6/-RESET
29
AVCC
18
VCC
4
VCC
6
GND
3
GND
5
GND
21
AREF
20
ADC619ADC7
22
GND
33
Y1
16MHzY116MHz
R11
2.2k
R11
2.2k
C1
10nC110n
Q1
PDTC115TU
Q1
PDTC115TU
R41MR4
1M
C2
10uC210u
C3
10nC310n
R90R9
0
C4
10nC410n
R20
470
R20
470
C5
10nC510n
C9
4.7pC94.7p
R12
3.3k
R12
3.3k
L1
2.7nL12.7n
C6
10nC610n
L2
8.2nL28.2n
U2
nRF24L01U2nRF24L01
ANT1
12
ANT2
13
IREF
16
VDDPA
11
VDD
18
VDD
7
VDD
15
DVDD
19
VSS
14
VSS
20
VSS
17
VSS
8
XC110XC2
9
CE1IRQ6CSN
2
SCK3MOSI4MISO
5
U1
SN11220ACF
U1
SN11220ACF
VDD
7
TAVDD
9
VDD
21
VSSA_PLLA
23
TAVSS
12
VDDOUT
35
VDD5D
36
VSS
37
VDD
46
VSSA_PLLB
48
XSDIN
24
XSCLK
25
XLRCK
26
XSDO
27
XMCLK
32
GPIO020GPIO144GPIO218GPIO3
30
PDSW
31
XOUSB28XIUSB29USBDP10USBDM
11
RSTN
13
SDA
42
SCL
43
LFB47LFA22DR1DW2SK3CS
4
LEDN
14
PADFUN0
5
PADFUN1
6
PADFUN2
41
PADFUN3
8
CODECSEL
45
VOLDN
15
VOLUP
16
MUTEP
17
HIDMUTER
19
MUTER
39
RECORD
38
FREQMODE0
40
FREQMODE1
34
FREQMODE2
33
C18
22p
C18
22p
L3
3.9nL33.9n
R25
1.5k
R25
1.5k
C11
10n
C11
10n
R1010R10
10
C24
470n
C24
470n
C16
15p
C16
15p
P1P1
123
4
R210R21
0
R80R8
0
C25
2.2u
C25
2.2u
R5
100kR5100k
U4
93C46U493C46
VCC
8
GND
5
CS
1
ORG
6
DO
4
SK
2
DI
3
C8
33nC833n
+
C23
47u+C23
47u
P3P3
11223344556
6
C10
2.2n
C10
2.2n
C13
10u
C13
10u
R322R3
22
C22
10u
C22
10u
C14
1.0p
C14
1.0p
C7
1.0nC71.0n
R24
10k
R24
10k
A1A1
1
1
C12
1.5p
C12
1.5p
R260R26
0
C26
1.0p
C26
1.0p
C15
15p
C15
15p
Y2
6.0MHzY26.0MHz
PCB1 nRF24L01 VoIP USB Dongle BoardPCB1 nRF24L01 VoIP USB Dongle Board
R1
22kR122k
R23
10k
R23
10k
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