NSB-7
UI Module
PAMS Technical Documentation
Page 16
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Nokia Mobile Phones Ltd.
Issue 1 06/00
Speaker
Speaker circuit includes pads for speaker and 2 capacitors, 2 ferrites for EMC protection.
The speaker is sealed to the A-cover with gasket and UI PCB with supporting light guide.
With that the frequency response is more constant. The speaker does not need holes for
PCB. This gives reliable sound quality for the phone and it can be estimated in several
environments. Arrangement is a leak tolerant speaker.
The low impedance, dynamic type earphone is connected to a differential output in the
COBBA audio codec. The electrical specifications for the earphone output are shown
below. The voltage level at each output is given as reference to ground. Earphone levels
are given to 32 ohm load.
Figure 9: Speaker
Nominal
Maximum
Notes
COBBA output, differential, 6dB
gain
17.6mV
788mV
ENGINE - UI Interface; Estimate,
must be checked with final ear-
piece construction
Earpiece sound pressure (sensitivity
+28dBPa/V 1kHz)
-7dBPa
+26dBPa
Measured as shielded (in brackets
with leak ring)