Sierra Wireless Q2687 Manuel D’Utilisation
Wireless CPU Quik Q2687
Interfaces
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WA_ENG_Q2687_PTS_001-002
September 11, 2006
3.14.2 Common Speaker Output Characteristics
The connection is single-ended on SPK1 and either a differential or single-ended on
SPK2.
SPK2.
Use of a differential connection to reject common mode noise and TDMA noise
is strongly recommended. Moreover, in single-ended mode, ½ of the power is lost
.
When using a single-ended connection, be sure to have a good ground plane, a good
filtering and also shielding, in order to avoid any disturbance on the audio path.
3.14.2.1 Differential Connection
Impedance of the speaker amplifier output in differential mode is shown below:
Parameter
Typ
Unit
Z (SPK2P, SPK2N)
8
Ω
3.14.2.2 Single-ended Connection
Impedance of the speaker amplifier output in single-ended mode is shown below:
Electrical Characteristics
Parameter
Typ
Unit
Z (SPK1P, SPK1N)
16 or 32
Ω
Z (SPK2P, SPK2N)
4
Ω
3.14.3 Speaker Outputs
3.14.3.1 Speaker 2 Outputs
Pin description of Speaker 2 outputs
Signal
Pin
number
I/O
I/O type
Description
SPK2P
39
O
Analog
Speaker 2 positive output
SPK2N
41
O
Analog
Speaker 2 negative output