User`s guide

Test Points
M1 System Management Board User’s Guide 27
Charging and Discharging Routines
The battery is charged/discharged using the two FET controls (Figure 2-13). When Q3 is turned On and Q2 is turned
Off, the constant current source (20 mA) will slowly charge up the 7.2 V battery. When Q3 is turned Off and Q2 is
turned On, the battery is placed in discharge mode and will power up the board and start discharging. All voltages and
current are monitored by the M1AFS1500-FG484 device. A number of algorithms can be designed in the M1AFS
device for implementing the charging and discharging routines of the battery.
Figure 2-13. Charging and Discharging Routines
For demonstration purposes, you can discharge the battery and place a jumper on JP3. This adds an extra 110 Ω load to
the battery output voltage.
Note: The above figure is not a complete representation of the board schematics.
Temperature Monitoring
Connect a temperature diode to header JP5 to monitor battery temperature. Charging/discharging algorithms monitor
battery temperature.
Battery Backup
If you need a constant battery backup without any discharging algorithms in the M1AFS1500-FG484 device, place a
jumper to JP27. This keeps Q2 On and puts the battery in discharge mode. Both the power brick and the battery are
connected, but the power brick powers up the board automatically because the power brick is at a higher voltage than the
battery. If the power brick is pulled out in the middle of operation, the battery supply takes over with no interruptions.
Test Points
Table 2-21 and Table 2-22 show various test points provided across the board, and how to access them.
AG AV AC AV ACAG
M7AFS
Battery Ouput
Power
Constant
Current Source
Input
Power
7.2V Battery
Q3 Q2
Table 2-21 · Test Points by Numerical Sequence
Test Points Signal Name
TP1 Digital 3.3 V
TP2 Digital GND
TP3 Digital GND