Specifications

Product Technical Specification & Customer Design Guidelines
Interfaces
3.11.4.2 Speaker
3.11.4.2.1 EAR Differential Connection
EARP
EARN
Figure 19: Example of Speaker differential connection
Impedance of the speaker amplifier output in differential mode is:
R
≤ 2Ω +/-10 %.
The connection between the Q64 pins and the speaker/earpiece must be designed to
keep the serial impedance lower than 3
Ω in the differential mode.
3.11.4.2.2 EAR Single-ended Connection
Typical implementation
:
Figure 20: Example of Earpiece/Speaker single-ended connection
4.7 μF < C1 < 47 μF (depending on speaker characteristics and output power).
A decoupling capacitor C3 is highly recommended to eliminate the TDMA noise. C3
must be close to the speaker.
Using a single-ended connection includes losing of the output power (- 6 dB)
compared to a differential connection.
The connection between the Q64 pins and the speaker must be designed to keep the
serial impedance lower than 1.5
Ω in the single-ended mode.
While using a single-ended connection in EAR, ensure to have a good ground plane, a
good filtering and shielding, in order to avoid any disturbance on the audio path. It is
recommended to use the Q64 Wireless CPU
®
AREF pin for the good plane connection.
If EARP channel is used, EARN can be left open.
If EARN channel is used, EARP can be left open.
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prior written agreement.
WA_DEV_Q64_PTS_001-003 January 9, 2009