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
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XT55/56_hd_v02.06a Page 73 of 125 17.12.2004
4.3.1 Trickle Power mode
The default mode of XT55/56 GPS part is continuous mode, but the user can set the
XT55/56 GPS part into the Trickle Power mode using the input command message. The
XT55/56 GPS part enters the Trickle Power mode corresponding to Figure 27 (800ms OFF
time and 200ms ON time) as soon as valid GPS data are available. As a result the average
power consumption is reduced by approximately 80 % (approximately 150mW). The settings
for the Trickle Power mode can be modified by using the SiRFstar demo software. For
example if the XT55/56 GPS part is configured to enter the OnTime mode each 10s for a
duration of 200ms the average power consumption can be reduced up to approx. 95%
(approx. 15mW, ca. 4.8mA at Vcc=3.3V). For more details refer to [1].
Figure 27: Example for current in Trickle Power mode