I am using an LTC6811-2 battery monitoring IC for monitoring a battery pack. I am also using an AD8205 to sense the current between battery and load. To control both ICs, I am using an STM32F401 microcontroller. I am using a 36V nominal 2500 mAh battery pack. Its maximum voltage is 42V.
Microcontroller power consumption:
- supply voltage : 3.3v
- input current : 160 mA max
AD805 (current sense amplifier ) power consumption :
- supply voltage : 5v
- input current : 20 mA
Since my microcontroller input supply voltage is 3.3V, I have used a buck converter to buck the voltage from 42V to 3.3V to give as an input voltage to my microcontroller.
The problem is the current sense amplifier supply voltage is 5V. I cannot use one more buck converter to get 5V again it will end up in more components and power loss.
Can I use the regulated output of my battery monitoring IC to power my current sense amplifier. In the datasheet of my IC is given like.
It is given like Vreg pin is used to power the internal SPI and ADC converters, but in my design I am giving the power of SPI through 3.3 v of microntroller. This is also mentioned in the datasheet.
Since I am not using Vreg output pin of my battery monitoring IC to power my SPI. Can I use it to power my current sense amplifier so that I can reduce the component count and reduce the extra power consumption. Like this:
Is it possible or should I go with the current sensing amplifier with 3.3 v as input voltage?
Please find the attached data sheet of battery monitoring IC : enter link description here
Current sensing amplifier datasheet:enter link description here