Telit Wireless Solutions GE864 Work Light User Manual


 
GE864 Hardware User Guide
1vv0300694 Rev.10 - 10/06/08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 23 of 69
5.2.1.3 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
GE864-QUAD/PY module.
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
GE864-QUAD/PY and damage it.
NOTE: DON’T USE any Ni-Cd, Ni-MH, and Pb battery types directly connected with GE864-QUAD/PY. Their
use can lead to overvoltage on the GE864-QUAD/PY 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 GE864-
QUAD/PY 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.