Hardware Guide
Table Of Contents
- Introduction
- 2. Overview
- 3. GE865 Mechanical Dimensions
- 4. GE865 module connections
- 5. Hardware Commands
- 6. Power Supply
- 7. Antenna
- 8. Logic level specifications
- 9. Serial Ports
- 10. Audio Section Overview
- 11. General Purpose I/O
- 11.1. GPIO Logic levels
- 11.2. Using a GPIO Pad as INPUT
- 11.3. Using a GPIO Pad as OUTPUT
- 11.4. Using the RF Transmission Control GPIO4
- 11.5. Using the RFTXMON Output GPIO5
- 11.6. Using the Alarm Output GPIO6
- 11.7. Using the Buzzer Output GPIO7
- 11.8. Indication of network service availability
- 11.9. RTC Bypass out
- 11.10. External SIM Holder Implementation
- 12. DAC and ADC section
- 13. Mounting the GE865 on your Board
- 14. Packing system
- 15. Conformity Assessment Issues
- 17. Document History
GE865 Hardware User Guide
1vv0300799 Rev.15– 2012-04-23
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 33 of 77
6.3.1.3. Battery Source Power Supply Design Guidelines
• The desired nominal output for the power supply is 3.8V and the maximum voltage
allowed is 4.2V, hence a single 3.7V Li-Ion cell battery type is suited for supplying the
power to the Telit GE865 module.
WARNING:
The three cells Ni/Cd or Ni/MH 3,6 V Nom. battery types or 4V PB types MUST NOT BE
USED DIRECTLY
since their maximum voltage can rise over the absolute maximum voltage
for the GE865 and damage it.
NOTE:
DON'T USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with GE865. Their use
can lead to overvoltage on the GE865 and damage it. USE ONLY Li-Ion battery types.
• A Bypass low ESR capacitor of adequate capacity must be provided in order to cut the
current absorption peaks, a 100μF tantalum capacitor is usually suited.
• Make sure the low ESR capacitor (usually a tantalum one) is rated at least 10V.
• A protection diode should be inserted close to the power input, in order to save the
GE865 from power polarity inversion. Otherwise the battery connector should be done in
a way to avoid polarity inversions when connecting the battery.
• The battery capacity must be at least 500mAh in order to withstand the current peaks of
2A; the suggested capacity is from 500mAh to 1000mAh.