TF4 Technical Information
In TFE-4/RV-1 the Slow ADCs of the UEM are only used for general status information for
which only low accuracy is needed. By this reason no calibration of the slow ADCs is
needed and by this reason the regarding calibration menu of phoenix is deactivated. Only
three AD-Converters of the UEM are activated on TFE-4/RV-1 (which can be read out by
the phoenix ADC-Readings) those are used in following way:
VBAT: this voltage monitors the voltage level of the TF-4 power supply, which is applied,
via the power-b2b connectors.
Btemp: there is a fixed resistor 47k mounted on TF-5 junction board. This in combination
with the 100kR pull-up-resistor will result in a BTEMP reading of typically 25°C (±3°C)
BSI: this input is used to monitor if the car battery voltage is in right level or to start the
TFE-4/RV-1 in local mode. There are three ranges BSI input can have:
Resulting operation mode
TFE-4/RV-1 will start in local mode when external resistor of <10k
is applied before car battery/ignition is activated
This is the normal operating mode
The car battery has wrong range; by this the BSI resistor of 47kR
is not connected to ground. Due to that the phone software can
detect that the car battery is not in the right range. This is used to
disable Simcard for protection purposes.
Copyright © 2005 Nokia Corporation.
Nokia Customer Care
Issue 2.0 Mar/2005