Siemens S55 Repair Documentation page 25

Measurement of Battery and Ambient Temperature
The battery temperature is measured via the voltage divider R1387, R138 by the
For this, the integrated Σ∆ converter of the RX-I base
EGOLD+
(Analog Interface P2).
band branch is used. This Σ∆ converter compares the voltage of
TBAT and TENV
internally. Through an analogue multiplexer, either the RX-I base band signal, or the
TBAT signal and the TENV signal is switched to the input of the converter. The signal
MEAS_ON from the EGOLD+ activates the battery voltage
(GSM TDMA-TIMER H15)
measurement The ambient temperature TENV is measured directly at of the EGOLD+
.
(Analog Interface P3)
Measurement of the Battery Voltage
The measurement of the battery voltage is done in the Q-branch of the EGOLD+, for
this BATT+ is connected via a voltage divider R143, R146 to the EGOLD+
(Analog
. An analogue multiplexer does the switching between the baseband signal
Interface P1)
processing and the voltage measurement.
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