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Nokia Customer Care
TF5 Technical Information
Company Confidential
TFE-4/RV-1
Issue 2.0 Mar/2005
Copyright
©
2005
Nokia Corporation.
Page 8a-13
Company Confidential
Description of the Hardware Realization
The power supply block consists of three power regulators and three power switches.
Vwake/Vmic
Vwake is the power, which supplies all circuitsthat have to be active when car battery is
applied. This power path has to be optimized for low leakage current to guarantee the
1mA standby demand. The Voltage VWAKE is used in the Power control block and as
Backup-Battery replacement for the EB. When HF-Audiopath is activated, (B2BHFMute is
high) the VWAKE power is directed to VMIC
B2BUIPOWERON UI-Power control signal
High: 1.6..18V
Low: 0..0.5V
Here: UIPOWER will always be
switched on with VEBPOWER
(when always high)
Or always off (when always low)
Outputs
VWAKE
Powersupply for VMIC,
Powerup control and
Engine-RTC
5V 5%
Unit will not wakeup
VEBPWR
Powersupply for Engine
and Headset Powerampli-
fier
Sleepmode:
0V
active:
4.2V 5%
Unit will not wakeup (when
always low)
Or Sleepmode current will be too
high (when always high)
VAudio
Powersupply for Hands-
free Poweramplifier
HF Poweramplifier will not work
VMIC
Phantom-Power for HF-
Microphone
0V when
switched off,
else 5V 5%
VMIC invisible on HFMIC con-
nector
VIDDU
Protected Power for Input
Device and Display Unit
0V when
switched off,
else 4V
UIPower or s.c. Protection will
not work
Signalname
Description
Range
When Error then .......
Inputs