I am designing some devices to track my machines capacity utilization data. I am using a tiny2313, a FM24C64 Fram memory chip and a DS1302.
The battery I plan to use is a ML2430 Lithuium
.5ma charge, constant voltage charge 3.1 +-0.15V
I am using the latest CodeVision C compiler that has a library for this parts communication.
The Fram needs 5VDC. I plan to use a larger battery to run the device for up to 30 days minimum. If I use a LDO regulator to power the tiny2313 and the DS1302 at 3.1V and a second LDO regulator to power the Fram at 5V.
Should I use a single diode and 2k resistor for the Trickle charge connection to the ML2430? I have some Shottky diodes I can use. Should I bump the voltage to the DS1302 so that the output of the trickle charger reaches 3.1V ?
After a bit more reading, I see the diode and resistors are internal to the DS1302 and set by software.
So it looks like i could use a regulator to power vcc2 at 3.8VDC and select 1 diode and 2k resistor to get 3.1V charge maximum at 1.9ma Once I looked at connecting it up adding a diode and resistor did not make much sense.