Backup battery problem for microcontroller.

[maniac84]

Hi guys,
I have a circuit which is using rabbit RCM6750 micro-controller. I hook it up with a 3V (620mAh) backup battery for RAM. But I found out that the battery drop to 1.5v in 3 months time only.
What I want to know is, generally not just for RCM6750, for other mcu also, what determine the amount of current it use on the backup battery? Does the firmware causes this? Or it's the hardware problem?
Is there a way to reduce it?

 

[Golden Electronics]

1. Depend on all circuit consumption.
2. Controller Operating Frequency & it's Power saving mode if any
3. Battery total capacity in Ampere hour capacity.
4. From this we get required Consumption & actual consumption diff.

 

[maniac84]

1. Depend on all circuit consumption.
2. Controller Operating Frequency & it's Power saving mode if any
3. Battery total capacity in Ampere hour capacity.
4. From this we get required Consumption & actual consumption diff.

Is there a way we could reduce the backup battery current consumption?

 

[Golden Electronics]

1. Use low frequency .
2. Operate controller in low power mode & if possible in Sleep mode if any
3. Increase resistance value if any according to Ur circuitry
4. Post Ur circuit for more details

 

[g_shyam1682]

HI,

Put micro in sleep mode whenever there is not any important work in progress in micro.

Regards,

 

[maniac84]

HI,

Put micro in sleep mode whenever there is not any important work in progress in micro.

Regards,

Sleep mode can only apply when the mcu is power on right?
What I want is after mcu power off, how do we reduce the current consumption from the backup-battery? Is there a way to reduce it? Or it is fixed?

 

[wp100]

Hi,

Have not used that micro, but a quick look at the datasheet details standby voltage and current for sram, controlled by the standby pin, so looks like the circuitry for low power RAM standby is already there for you to use.

Apart from that, is probably wise to store all your key ram values in eeprom so if all power is lost the data is still retained.
Your program code should be set to copy the eeprom values back in ram when it starts up.

 

[maniac84]

Hi,

Have not used that micro, but a quick look at the datasheet details standby voltage and current for sram, controlled by the standby pin, so looks like the circuitry for low power RAM standby is already there for you to use.

Apart from that, is probably wise to store all your key ram values in eeprom so if all power is lost the data is still retained.
Your program code should be set to copy the eeprom values back in ram when it starts up.

So what you mean is that there is no way we could reduce the current consumption on backup battery during power off and it is fixed by the manufacturer of the mcu?