Headset Reference Design v1.0
3 Hardware description
3.1nRD24V1 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,
5
1
4
2
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| 3 |
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1 | RF crystal | 4 | Audio codec |
2 | nRF24L01 | 5 | MCU crystal |
3 | MCU |
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Figure 5. nRD24V1 radio module
3.1.1Audio Codec
The audio codec is a XE3005 from Semtech that receives a 4.096 MHz master clock from the micro con- troller. 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.
Revision 1.0 | Page 7 of 25 |
