User Guide

CCS Technical Documentation System Module

RH-27

reasons, the phone software will shut the phone off if it senses a temperature of 38

C or

higher on BTEMP line.

Figure 2: Interconnection diagram

Supply Voltage Regulation

The UEM ASIC controls supply voltage regulation. There are six separate regulators used

by the baseband block. For a more detailed description about the regulator parameters,

see the document UEM ASIC Specification.

Charging

RH-27 baseband supports the NMP charger interface specified in the document Janette

Charger interface, SW control is specified in EM SW Specification, ISA EM Core SW

Project. The UEM ASIC controls charging, and external components are used to provide

EMC, reverse polarity, and transient protection of the charger input to the baseband

module. The charger connection is through the system connector interface. Both 2- and

3-wire type chargers are supported. The operation of the charging circuit has been spec-

ified to limit the power dissipation across the charge switch and to ensure safe operation

in all modes.

Table 3: BSI resistor values

Parameter Min Typ Max Unit Notes

Battery size indicator resistor BSI 75 kΩ Battery size indicator (BLD-3)

Tolerance “1%

NTC thermistor BTEMP 47

4000

kΩ

Battery temperature indica-

tor (NTC pulldown) 47kΩ“5%

@ 25

Beta value (B).

Tolerance “5%, 25

C / 85

Overcharge /

Overdischarge

protection

VBATT

BSI

BTEMP

EMC

Li-Ion