User Guide

TME-3 Company Confidential
Data Module RL7 PAMS Technical Documentation
Page 16 Nokia Corporation. Issue 4 12/03
Functional Description
POWER
TME-3 operates with external DC wall power supply without a battery. The DC voltage
can be supplied either trough the DC jack or the M2M system connector. TME-3 has a
wide supply range high efficiency synchronous switched mode step-down converter,
which regulates the input voltage down to normal battery voltage level (3.6V).
Power Distribution
Input voltage from DC connector or M2M system (VBB) is fed to step-down DC-DC con-
verter, which regulates the voltage to 3.6V. The 3.6V is fed to DCT4 power management
circuit UEM (VBAT), to a 3V3 LDO and to the RF power amplifier (VBATRF). UEM regulates
VBAT further for baseband and RF. The 3V3 LDO is used for M2M system I/O buffers.
VBAT is fed to M2M system connector through a switch controlled by UPP.
An application can also draw current directly from the fused input voltage (VBB). The
available current depends on the input voltage and the power consumption of TME-3.
Typical maximum power consumption of TME-3 is less than 5.5 W (including the 300 mA
power feed to the application) in all circumstances. For example, if the input voltage is
12.0 V, the application can draw at most 2A - 5.5 W / 12 V = 1540 mA of current with-
out blowing the fuse. However, it is advisable to derate the fuse current to 75% or 1.5 A,
which in the example above leaves ~1000 mA current for the application.
Figure 8: TME-3 power distribution.
UEM
UEM is an energy management IC. In addition to energy management functionality the
UEM performs all the baseband mixed-signal functions.
User Interface
The TME-3 user interface consist of three two-coloured (green/red) leds.
BB
regulators
DC
Jack
DC/DC
Step-down
converter
VBB
RFC
60R/100M
RFC
60R/100M
3 x 680u
3 x 680u
PA
3V3
LDO
UEM
AIF
I/O buffers
Load switch
RF
regulators
A
I
F
VBATRF
VBAT
680u
4.75 V - 15.0 V power feed
from AIF
Power feed/indication
to AIF
AIF_3V3
VCCAM
300mA power
feed to AIF
Control
from UPP
VIN
6.5 V - 8.2 V
To UPP
Power fail
indicator