Specifications

Wireless CPU
®
Q24 Series
Interfaces
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prior written agreement.
WM_PGM_Q24NG_PTS_001-005 November 20, 2007
3.12 Audio Interface
Two different microphone inputs and two different speaker outputs are supported.
The Wireless CPU
®
Q24 Seri include an ec ncellation feature, which allows
hands-free operation.
es also ho ca
Caution:
When speakers and microphones are exposed to the external en ment, it is
recommended to add ESD protection on the audio interface lines.
3.12.1 Microphone Inpu
The MIC2 already incl e biasing for tret micropho s allowing
easy connect o a handset.
The MIC1 inputs do not include an internal bias. MIC1/SPK1 may be used for a
hands-free system or a handse for the microphone.
The microph ended, but using a
viron
ts
inputs ude th an elec ne, thu
ion t
t, including biasing circuit
one connections may be either differential or single-
differential connection in order to reject common mode noise and TDMA noise is
strongly recommended.
Caution:
While using a single-ended connection, ensure to have a good ground plane, a good
filtering as well as shielding, in order to avoid any disturbance on the audio path.
Input Characteristics
Both microphone inputs are e following audio transmit
characteristics:
audio filter cha
3.12.1.1 Common Microphone
designed with th
Internal racteristics
Frequency Gain
0-150 Hz < -22 dB
150-180 Hz < -11 dB
180-200 Hz < -3 dB
200-3700 Hz 0 dB
>4000 Hz < -60 dB
The gain in the MIC inputs are internally adjusted and may be tuned from -6.5 dB to
51.3 dB by using AT commands (refer to AT commands documentation [4]).