Battery Charge Level Limits On Cmt And Pda - Nokia 9000i Service Manual

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Battery charge level limits on CMT and PDA

Figure 5 (overleaf) shows an example of combined CMT and PDA critical
battery levels, measurement accuracy (+/– 50mV). There are two kind of
limits most of which are implemented in software.
The AD converter, located in the CMT module, is used as a source for
battery level values needed by both CMT and PDA software. PDA gets
battery level information from the AD converter via ECI messages. The
CMT HW limit, PDA HW cut–off and Battery protect circuit cut–off are
implemented in hardware and actions are taken without notice to any
software.
The following limits are based on battery level values read from the AD
converter; decisions are made by software.
S
Battery low level warning 1
S
CMT battery cut–off
S
Battery low level warning 2
S
PDA limit (Data save)
The following limits are implemented in hardware:
S
CMT HW limit
S
PDA HW cut–off
S
Battery protect circuit cut–off
Original, 08/96
If CMT is ON this warning is generated by
CMT sending a message to PDA when warning 1 is
triggered. If CMT is OFF, PDA must generate this
warning itself.
CMT switches itself off when battery level has fallen
below this level.
PDA generates this warning when the battery level
value read from CMT has fallen below this level.
PDA saves all user data and disables PDA when
the battery level is below this level.
CMT power supply switches itself off.
PDA power supply switches itself off.
A circuit in the battery package switches power off
from battery output pads.
RAE/RAK–1N
PDA Hardware
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