TFE-4/RV-1 Company Confidential
TF5 Technical Information Nokia Customer Care
Page 8a-18 Copyright © 2005 Nokia Corporation. Issue 2.0 Mar/2005
Company Confidential
Power control/Reset Blockdiagram
Figure 12: Block diagram of Power control/Reset Block
The Vcar-Check Block is responsible to monitor if the Vcar is within operating range.
When the voltage range of the car battery is too high or to low Powerok line will be low
and the board will not start up anymore. By holding B2BPOWEROFF high, the Phone-
Engine can force the Power supply to switch off when ignition sense input is low. The
Poweronx block generates pulses of 0.5Hz, when Vebpwr is active.
Description of Inputs, Outputs and Block-Internal Lines
Signalname Description Range When Error then .......
Inputs
VCAR Protected Carbattery Voltage Defined: 5V..20V
Operating: 9..15V
Whole unit will not work
SENSE Ignition Sense signal from
Carconnector
Low: 0..8V
high (active
mode):
8..28V
Unit will not wakeup (when
always low)
or sleepmode current will be
too high (when always high)
VWAKE Powersupply for VMIC,
Powerup control and
Engine-RTC
5V 5% Unit will not wakeup
B2BPOWEROFFX Control signal from Engine-
board to switch off SMPSon
after Ignition is switched off
High: 1.6..18V
Low: 0..0.5V
SMPSon will always keep
active (when always low) or
goes immediately low when
ignition is switched off
(when always high)
Vcarchec
k
SMPSStartup
PoweronX
IGNS
Levelshi
fter
POWEROK
Vwake
Vcar
Sense
IGNS5V
B2BPOWEROFFX
B2BPOWERONX
SMPSON
B2BIGNS
BSI-
switch
BSI POWEROK
VEBPWR
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