Specifications

Wireless CPU
®
Q24 Series
Interfaces
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This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without
prior written agreement.
WM_PRJ_Q24NG_PTS_001-004
January 16, 2007
Microphone gain versus Max input voltage
Using Controller 1 Using Controller 2
Transmit Gain
(dB)
Max Vin (mVrms) Transmit Gain (dB) Max Vin (mVrms)
+30 43.80 -6.5 3031
+33 31.01 -6 2861
+36 21.95 0 1434
+39 15.54 +9.5 480
+42 11 +10 454
+45 7.79 +30.3 43.80
+48 5.51 +30.8 41.36
+51 3.9 +50.8 4.14
- - +51.3 3.90
* For more details, refer to the AT commands documentation [4]
3.12.1.2 MIC1 Microphone Inputs
The MIC1 inputs are differential and do not include internal bias
. To use these inputs
with an electret microphone, bias must be generated outside the Wireless CPU
®
Q24
Series in accordance with the characteristic of this electret microphone. These inputs
are the standard inputs used either for an external headset or a hands-free kit.
The impedance of microphone 1 must be around 2 kΩ. AC coupling is already
embedded in the Wireless CPU
®
.
Equivalent circuits
DC equivalent circuit AC equivalent circuit