Specifications

Wireless CPU
®
Q24 Series
Interfaces
©Confidential Page: 46 / 83
This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without
prior written agreement.
WM_PRJ_Q24NG_PTS_001-004
January 16, 2007
3.14 Battery Charging Interface
3.14.1 Hardware Description
Caution:
The battery charging interface does not allow
the Wireless CPU
®
to be supplied and is
only used to charge a battery connected to VBATT.
Battery charging is performed through a switching transistor connecting the VBATT
signal to the Charger (CHG_IN signal).
The switching transistor is controlled by the operating system with two kinds of
algorithms.
Equivalent circuit
The Wireless CPU
®
Q24 Series supports three types of battery technologies:
• Ni-Cd (Nickel-Cadmium), which is charged with the algorithm 0
• Ni-Mh (Nickel-Métal Hydrure), which is charged with the algorithm 0
• Li-Ion (Lithium-Ion), which is charged with the algorithm 1
The algorithm controls the frequency and the connected time of switching transistor
(T).
To select the algorithm:
• AT+WBCM=4,0Æ Ni-Cd/Ni-Mh (by default)
• AT+WBCM=4,1ÆLi-Ion
• AT+WBCM=4,2ÆTo know which algorithm is used
During the charging procedure, battery charging level is controlled.
BAT_TEMP
Q24 Series
CHG_IN
Charger controller
5K6
T
Charger
detection
VBATT