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
Electrical characteristics
MIC2 Electrical characteristics
Parameters Min Typ Max Unit
MIC2- 0.225 0.35 0.475 V
MIC2+ 2.025 2.15 2.275 V
Output
current
0.5 1 mA
Internal biasing
DC
characteristics
R2 900 1150 1400
Ω
AC
characteristics
100 Hz<F<5
kHz
Z2 1.2 1.5 1.8
KΩ
3.12.2 Speaker Outputs
Two speaker outputs are available: SPK1 and SPK2.
Both speaker outputs may be represented as follows:
Equivalent circuit
3.12.2.1 Common Speaker Output Characteristics
The connection may be differential or single-ended, but using a differential connection
to reject common mode noise and TDMA noise is strongly recommended. Moreover,
in single-ended mode, the power is reduced by two, compare to the differential mode
Caution:
When using a single-ended connection, ensure to have a good ground plane, a good
filtering as well as a good shielding in order to avoid any disturbance on the audio
path.
Speaker outputs SPK1 and SPK2 are push-pull amplifiers and may be loaded down to
150Ω and up to 1 nF
The impedance of the speaker amplifier outputs in differential mode is:
R ≤ 1 Ω +/-10 %.
When speaker output is not used, the speaker interface is in three states and a 20K
+/-30% impedance is kept between SPK1N and SPK1P as well as SPK2N and SPK2P.
These outputs are differential and the output power may be adjusted by step of 2 dB.
The output may be directly connected to a speaker.
The gain in the speaker outputs are internally adjusted and may be tuned by using AT
commands (refer to the AT commands documentation
[4]).
Q24 Series