D
Didi
I am scratching my head how to power an RTC chip (apr. 3uA) and
I think I'll drop all these NiCd or NiMH rechargables and use a
lithium
battery which should last for 7 years (and costs 5-6 times less).
Now I began thinking what will happen if I use a Shottky diode, say,
a BAT43 to draw power from the battery while the system is off.
It will work this way, no doubt about that. But when the system
is on - and if the diode gets hot - it may try to "charge" the battery
with some microamps, perhaps tens of microamps (battery being
some 20mm diamater lithium thikish button cell). The diode is
specified
at 100C and 25V reverse voltage at a max. of 100uA....
Will the battery endure this? Now it will clearly be less, the diode
will
be exposed to perhaps 1 or 2 volts max., but I don't know what the
reverse current would be then and frankly I will be equally in the
dark if it is 1 uA, I just don't know how the lithium button cells
behave.
Thanks,
Didi
I think I'll drop all these NiCd or NiMH rechargables and use a
lithium
battery which should last for 7 years (and costs 5-6 times less).
Now I began thinking what will happen if I use a Shottky diode, say,
a BAT43 to draw power from the battery while the system is off.
It will work this way, no doubt about that. But when the system
is on - and if the diode gets hot - it may try to "charge" the battery
with some microamps, perhaps tens of microamps (battery being
some 20mm diamater lithium thikish button cell). The diode is
specified
at 100C and 25V reverse voltage at a max. of 100uA....
Will the battery endure this? Now it will clearly be less, the diode
will
be exposed to perhaps 1 or 2 volts max., but I don't know what the
reverse current would be then and frankly I will be equally in the
dark if it is 1 uA, I just don't know how the lithium button cells
behave.
Thanks,
Didi
