User's Manual

GE864- QUAD Har dwar e User Guide

1vv0300872 Rev.1 2010-04-02

As you can see, the charging process is not a trivial task to be done; mor eover all

these operations must start only if battery temperature is inside a charging range,

usually 5°C – 45°C.

The GE864-QUAD measur es the temper ature of its inter nal component, in order to

satisfy this last requirement, it is not exactly the same as the battery temper ature

but in common application the two temper atur e must not differ too much and the

charging temper ature range must be guaranteed.

NOTE:

For all the threshold voltages, inside the GE864-QUAD all thresholds are fixed in

order to maximize Li-Ion batter y perfor mances and do not need to be changed.

NOTE:

In this application the battery charger input cur r ent must be limited to less than

400mA. This can be done by using a cur r ent limited wall adapter as the power

source.

NOTE:

When starting the char ger from Module power ed off the startup will be in CFUN4; to

activate the nor mal mode a command AT+CFUN=1 has to be provided. This is also

possible using the POWER ON.

There is also the possibility to activate the nor mal mode using the ON_OFF* signal.

In this case, when HW power ing off the module with the same line (ON_OFF*) and

having the charger still connected, the module will go back to CFUN4.

NOTE:

It is important having a 100uF Capacitor to VBAT in order to avoid instability of the

charger circuit if the battery is accidentally disconnected dur ing the charging activity.

6.2.2. Thermal Design Guidelines

The thermal design for the power supply heat sink must be done with the following

specifications:

Aver age current consumption dur ing transmission @ max PWR level:

500mA

Aver age current consumption dur ing transmission @ min PWR level:

100mA

Aver age current during Power Saving (CFUN=5): 4mA

Aver age current dur ing idle (Power Saving disabled): 24mA