Telit EVK2 User Guide
1vv0300704 Rev.13- 2012/06/25
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page
34 of 149
9.2.
High AF Power Mode
Connecting an
8 ohm
Speaker to PL401 by a 2 contacts female connector, you could drive it
through the 500mW Power Amplifier.
In this case the Speaker will be driven in fully differential configuration, with no side
connected to ground and without any output coupling capacitor. Therefore care must be
taken because there is DC voltage on both sides of the Speaker.
The overall gain of this amplifier can be modified varying the ratios R406/R404 and
R407/R410:
410
407
2
406
404
2
R
R
R
R
A
v
if R404=R407 and R406=R410
NOTE:
The coil impedance of the Speaker should be higher than 8 ohm @ 1KHz .
Figure 16: Speaker insertion
speaker.skd
STACKED
RS232
USB
RS232
1
CS113
9
40
39
SEPARATE
SPEAKER
1
AUDIO 2
AUDIO 1
30
29
PL1
0
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from