I built a very low power circuit that consumes about 15 µA at 6V from an array of four 1.5V batteries in series. Said batteries are connected to a 3.3V regulator which in turn feeds a small MCU. I would like to have another set of batteries in standby that could kick in when the first set of batteries are nearly depleted and have the MCU itself switch between them without a glitch. Below is a very simplified diagram of the circuit I'm trying to explain, sans the regulator.
I know how to measure the batteries' voltage to determine when to perform said switch, but I'm not sure about the best circuit to switch between the arrays using the MCU itself without a glitch that could accidentally interrupt power. Any ideas?
I know how to measure the batteries' voltage to determine when to perform said switch, but I'm not sure about the best circuit to switch between the arrays using the MCU itself without a glitch that could accidentally interrupt power. Any ideas?