Nokia Customer Care TF5 Technical Information
Company Confidential TFE-4/RV-1
Issue 2.0 Mar/2005 Copyright © 2005 Nokia Corporation. Page 8a-27
Company Confidential
HDMUTE Level shifter
Figure 25: HDMute Level shifter Realization
The B2BHDMUTEX signal, that is used by the phone engine to activate or deactivate the
HD-Power amplifier is converted here from 1.8V logic level of the engine to 4.2V level
used by the power amplifier. This logic inverts the signal of the control output.
Filter
This part filters the audio signals from EB and mainly cares to close up the symmetric
B2BXEAR lines when JB is standalone without phone engine.
Figure 26: B2BXEAR Filter
Level shifter Description
Block Diagram of Levelshifter Part
Figure 27: Block-Diagram of Level shifter Block
To HDSPKR
and HFSPKR
B2BCRM
CRM
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