Nokia 5140 Manuales De Servicio
NPL-4/5
System Module and User Interface
Nokia Customer Care
Page 38
Copyright © 2004 Nokia Corporation. All rights reserved.
Issue 1 05/04
Electrical compass
The compass will have two magnetometer channels and it uses anisotropic magnetore-
sistive (AMR) magnetometer component (containing both X- and Y-axes). Each measure-
ment axis is configured as a 4-element Whetstone bridge converting the magnetic field
into differential output voltage. This sensor element is capable of sensing fields in milli-
gauss range. In order to achieve the measurement resolution, the sensor must be fre-
quently reset by a current pulse run through the set/reset coil of the sensor element. The
MagIC ASIC will interface the phone engine through the CBUS interface. The calculation
of the compass heading and the calibration of the magnetometer are carried out in the
phone engine.
sistive (AMR) magnetometer component (containing both X- and Y-axes). Each measure-
ment axis is configured as a 4-element Whetstone bridge converting the magnetic field
into differential output voltage. This sensor element is capable of sensing fields in milli-
gauss range. In order to achieve the measurement resolution, the sensor must be fre-
quently reset by a current pulse run through the set/reset coil of the sensor element. The
MagIC ASIC will interface the phone engine through the CBUS interface. The calculation
of the compass heading and the calibration of the magnetometer are carried out in the
phone engine.
NPL-4/5 will have an air-bubble for the user to level the device.
The heading is shown by compass rose in phone display.
Figure 8: Baseband and Compass Interface
Thermometer
The 1% accuracy NTC-resistor is used for ambient temperature measurement. NTC resis-
tor sensor is located on UI-board under the keypad shield. It is connected with two A/D –
lines (AuxDet and Headint2) to UEMEK.
tor sensor is located on UI-board under the keypad shield. It is connected with two A/D –
lines (AuxDet and Headint2) to UEMEK.
Voltages are measured over 1% accuracy resistor that is connected series with tempera-
ture sensor. This gives sufficient accuracy for temperature measurement without calibra-
tion.
ture sensor. This gives sufficient accuracy for temperature measurement without calibra-
tion.
UEME
MagIC
DVdd
DVdd
AVdd
Clr
PURX
VIO
Clk
CBUS
GenIO3
2.8V
Regulator
UPP
GenIO1
Magneto
meter
S/R
y-axes
x-axes
Vbridge
UEMEK