TF5 Technical Information
Power control/Reset Blockdiagram
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
Protected Carbattery Voltage Defined: 5V..20V
Ignition Sense signal from
Powersupply for VMIC,
Powerup control and
B2BPOWEROFFX Control signal from Engine-
board to switch off SMPSon
after Ignition is switched off
Figure 12: Block diagram of Power control/Reset Block
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Nokia Customer Care
When Error then .......
Whole unit will not work
Unit will not wakeup (when
or sleepmode current will be
too high (when always high)
Unit will not wakeup
SMPSon will always keep
active (when always low) or
goes immediately low when
ignition is switched off
(when always high)
Issue 2.0 Mar/2005