I want to use MS621FE rechargeable lithium battery as RTC battery.
The working voltage of my circuit is 3.3V.
MS621FE allows a charge voltage from 3.1V to 3.3V.
To prevent the battery try to supply the system I need a diode series with the battery to the VDD.
The problem is,I want to charge the battery the most possibly full, and the lowest reverse current when system is powered-down, which means I need a diode with both low forward voltage(<0.2V) and low reverse current(<0.2uA), is it possible?
I found IN4148, but the forward voltage is too high, and some Schottky diode has the low enough forward voltage, but the reverse current is too high (10uA+).
Current consumption of my RTC module is only 1.4uA, I think I should find a diode whose reverse current is lower than 0.2uA to reach the minimum cost.