User Guide

SIM interface voltage is first 1.8V when the SIM card is inserted and if the card does not response to the ATR
(answer to reset) 3V interface voltage is used.
Battery interface
The battery interface supports a 3-pole battery interface. The interface consists of three connectors: VBAT,
BSI and GND.
The BSI line is used to recognize the battery capacity by a battery internal pull down resistor.
Figure 56 Battery pin order
Table 13 Battery interface connections
Pin Signal I/O Engine connection Notes
1 VBAT -> EM ASIC N2200 VBAT Battery voltage
2 BSI -> EM ASIC N2200 BSI Battery size
indication
(fixed resistor
inside the
battery pack)
3 GND GND Ground
Battery temperature is estimated by measuring separate battery temperature NTC via the BTEMP line, which
is located on the transceiver PWB, at a place where the phone temperature is most stable.
For service purposes, the device SW can be forced into local mode by using pull down resistors connected to
the BSI line.
RM-198
System Module Nokia Customer Care
Issue 1 COMPANY CONFIDENTIAL Page 8 –11
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