wolf12
Advanced Member level 4
I'm using a tiny RTC module to get time and I want to make the micro controller sleep when not in use.
With SDA and SCK of tiny RTC disconnected from 16F876A I get a sleep current of 0.25mA. Pull ups are 10K.
With SDA and SCK connected I get a sleep Current of 1.7mA. Pull ups are 10K.
If I change pull ups to 470K Sleep current is 0.25mA. The device functions with 470K. But I haven't seen anyone using 470k. Is 470K too much?
Also with 10K pullups, If I just disconnect GND from tiny RTC sleep current is 0.25mA.
With 470K pullups, GND disconnected, Sleep current is 0.70mA
Is it ok to disconnect GND using a transistor with data lines still connected to tiny RTC?
I need the lowest possible sleep current.
Also is it possible to lower the sleep current more. Currently I have disabled ADC, timers, Comparators, All interrupts except RB0, And tied all IO pins to +ve or -ve and set the ports as inputs.
Thank you.
With SDA and SCK of tiny RTC disconnected from 16F876A I get a sleep current of 0.25mA. Pull ups are 10K.
With SDA and SCK connected I get a sleep Current of 1.7mA. Pull ups are 10K.
If I change pull ups to 470K Sleep current is 0.25mA. The device functions with 470K. But I haven't seen anyone using 470k. Is 470K too much?
Also with 10K pullups, If I just disconnect GND from tiny RTC sleep current is 0.25mA.
With 470K pullups, GND disconnected, Sleep current is 0.70mA
Is it ok to disconnect GND using a transistor with data lines still connected to tiny RTC?
I need the lowest possible sleep current.
Also is it possible to lower the sleep current more. Currently I have disabled ADC, timers, Comparators, All interrupts except RB0, And tied all IO pins to +ve or -ve and set the ports as inputs.
Thank you.