Internal Speaker; Ihf Speaker - Nokia RH-37 Series Manual

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Internal speaker

The internal earpiece is a dynamic earpiece with an impedance of 32 ohms. The earpiece
is low impedance one since the sound pressure is to be generated using current and not
voltage as the supply voltage is restricted to 2.7V. The earpiece is driven directly by the
UEMEK and the earpiece driver (EARP & EARN outputs) is a fully differential bridge
amplifier with 6 dB gain.

IHF speaker

UEMEK has an integrated Audio power amplifier to generate output for the IHF speaker.
Issue 1 07/04
Figure 6: Internal microphone connection
Figure 7: Speaker connection
©Nokia Corporation
RH-37
System Module
Page 23