Specifications

Product Technical Specification & Customer Design Guidelines
Interfaces
Electrical characteristics of MIC1
Parameters Min Typ Max Unit
MIC1+ 2 2.1 2.2 V
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WA_DEV_Q64_PTS_001-003 January 9, 2009
Output current 0.5 1.5 mA
Internal biasing
DC Characteristics
Ω
R2 1650 1900 2150
Z1 MIC1P
(MIC1N=Open)
Z1 MIC1N
(MIC1P=Open)
1.1 1.3 1.6
Z1 MIC1P
(MIC1N=GND)
Z1 MIC1N
(MIC1P=GND)
0.9 1.1 1.4
AC Characteristics
KΩ
200 Hz<F<4 kHz
Impedance
between
1.3 1.6 2
MIC1P and
MIC1N
AT+VGT*=2 13.8
AT+VGT*=1 77.5
Maximum working
voltage
mVrms
( MIC1P-MIC1N)
AT+VGT*=0 346
Positive +7.35** Maximum rating
voltage
V
Negative -0.9
(MIC1P or MIC1N)
• *The input voltage depends on the input microphone gain set by AT command. Please refer to the
document
[4] AT Command Interface Guide for Open AT® Firmware v6.5
• **Because MIC1P is internally biased, it is necessary to use a coupling capacitor to connect an
audio signal provided by an active generator. Only a passive microphone can be directly connected
to the MIC1P and MIC1N inputs.
3.11.1.1.2 Auxiliary Microphone Inputs (AUXI)
The AUXI input is configured in single-ended.
The AUXI input does not include an internal bias. The AUXI input needs to have an
external biasing if an electret microphone is used.
AC coupling is already embedded in the Q64 Wireless CPU
®
.
Equivalent circuits of AUXI
DC equivalent circuit AC equivalent circuit
Z2
AUXI
DC
Blocked
A
UXI
GND