User guide

UC864-E/G/WD/WDU Hardware User Guide

1vv0300766a Rev.4

- 03/02/09

The UC864-E/G/WD/WDU measures the temperature of its internal component in

order to satisfy this last requirement. This not exactly the same as the battery

temperature but in common use, the two temperatures must not differ too much and

the charging temperature range must be guaranteed.

5.2.2. Thermal Design Guidelines

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

specifications:

• Average current consumption during HSDPA transmission @PWR level

max in UC864-E/G : 730mA

• Average current consumption during class12 GPRS transmission @PWR

level max: 790mA

• Average GPS current during GPS ON (Power Saving disabled) in UC864-

G : 110mA

NOTE:

For all the threshold voltages, inside UC864-E/G/WD/WDU, all thresholds are fixed in

order to maximize Li-Ion battery performances and do not need to be changed.

NOTE:

In this application the battery charger input current must be limited to less than

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

source.

NOTE:

When starting the charger from Module powered off, the startup will be in CFUN4; to

activate the normal mode a command AT+CFUN=1 has to be provided.

There is also the possibility to activate the normal mode using the ON_OFF* signal.

In this case, when HW powering 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 to have a 100ųF Capacitor to VBAT in order to avoid instability of the

charger circuit if the battery is accidentally disconnected during the charging activity.