User's Manual
Table Of Contents
- 1 Overview
- 2 GE864-QUAD Automotive V2 Mechanical Dimensions
- 3 GE864-QUAD Automotive V2 module connections
- 4 Hardware Commands
- 5 Power Supply
- 6 Antenna
- 7 Logic level specifications
- 8 Serial Ports
- 9 Audio Section Overview
- 10 General Purpose I/O
- 10.1 GPIO Logic levels
- 10.2 Using a GPIO Pad as INPUT
- 10.3 Using a GPIO Pad as OUTPUT
- 10.4 Using the RF Transmission Control GPIO4
- 10.5 Using the RFTXMON Output GPIO5
- 10.6 Using the Alarm Output GPIO6
- 10.7 Using the Buzzer Output GPIO7
- 10.8 Indication of network service availability
- 10.9 RTC Bypass out
- 10.10 External SIM Holder Implementation
- 11 DAC and ADC section
- 12 Conformity Assessment Issues
- 14 Document Change Log
GE864-QUAD Automotive V2 Hardware User Guide
1vv0300840 Rev.0.1 24/11/09
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 26 of 65
5.3.2 Thermal Design Guidelines
The thermal design for the power supply heat sink should be done with the following specifications:
• Average current consumption during transmission @PWR level max: 500mA
• Average current consumption during transmission @ PWR level min: 100mA
• Average current during Power Saving (CFUN=5): 4mA
• Average current during idle (Power Saving disabled) 24mA
NOTE: The average consumption during transmissions depends on the power level at which the device is requested
to transmit by the network. The average current consumption hence varies significantly.
Considering the very low current during idle, especially if Power Saving function is enabled, it is
possible to consider from the thermal point of view that the device absorbs current significantly only
during calls.
If we assume that the device stays into transmission for short periods of time (let's say few minutes)
and then remains for a quite long time in idle (let's say one hour), then the power supply has always
the time to cool down between the calls and the heat sink could be smaller than the calculated one for
500mA maximum RMS current, or even could be the simple chip package (no heat sink).
Moreover in the average network conditions the device is requested to transmit at a lower power level
than the maximum and hence the current consumption will be less than the 500mA, being usually
around 150mA.
For these reasons the thermal design is rarely a concern and the simple ground plane where the
power supply chip is placed can be enough to ensure a good thermal condition and avoid overheating.
For the heat generated by the GE864-QUAD Automotive V2, you can consider it to be during
transmission 1W max during CSD/VOICE calls and 2W max during class10 GPRS upload.
This generated heat will be mostly conducted to the ground plane under the GE864-QUAD Automotive
V2; you must ensure that your application can dissipate it.