User's Manual
Table Of Contents
- Contents
- Figures
- Tables
- Document history
- Introduction
- Product concept
- GSM application interface
- GSM/GPRS operating modes
- Power supply
- Power up / down scenarios
- Automatic GPRS Multislot Class change
- Charging control of the GSM part
- Power saving
- Summary of state transitions (except SLEEP mode)
- RTC backup for GSM part of XT55/56
- Serial interfaces of the XT55/56 GSM part
- Audio interfaces
- SIM interface
- Control signals
- GPS application interface
- GSM and GPS antenna interfaces
- Electrical, reliability and radio characteristics
- Mechanics
- Reference approval
- Example applications
- List of parts and accessories
XT55/56 Hardware Interface Description
Confidential / Released
s
XT55/56_hd_v02.06a Page 97 of 125 17.12.2004
6.4.1 Current consumption during GSM transmit burst
The diagrams provided in Figure 46 and Figure 47 illustrate the typical current consumption
of the application caused during a transmit burst. The typical peak current is shown vs. the
power control level for 900 MHz, 1800 MHz and 1900 MHz and vs. the return loss of the
antenna.
Test conditions: All measurements have been performed at T
amb
= 25°C, V
GSM_BATT+ nom
= 4.1V.
Reference points for measuring the voltage are the GSM_BATT+ and GND test points on the
back side of the module. The curves are for one TX slot (for example a voice call, CSD call
or Class 8 GPRS). Curves for Class 10 GPRS activities (2 TX slots) are shown too.
Changing the conditions, e.g. in terms of temperature or voltage, will cause different results.
Average Current GSM900 (V
BATT+
=4.1V)
0.10
0.10
0.11
0.15
0.21
0.25
0.13
0.14
0.16
0.23
0.33
0.43
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
5 7 9 1113151719
Power Control Level
Current (Amps)
1 TX - Average Current
2 TX - Average Current
Figure 41: Typical current consumption vs. return loss in EGSM 900 network