I would like to power two different components with two different voltages in my circuit.
- Component 1 : STM32F401 microcontroller (3.3V and 160 mA)
- Component 2: AD8205 current sensing amplifier (5V and 20 mA)
In my circuit I am using a battery pack of 36V nominal and 42V maximum as a source. First I have an LTC3638 buck converter to get 5V and 250 mA as output. From this I can source my current sensing amplifier. I want to power my microcontroller also so for that I am planning to use an ADP151 voltage regulator to get constant 3.3V to power the microcontroller.
ADP151 has very low power consumption, so it is safe to use.
I am planning to use the output of the buck converter (5V) as input of the voltage regulator to get 3.3V so that I can use 5V for my current sensing amplifier and 3.3V for my microcontroller.
When I simulate both the components separately using LT spice it is working perfectly and giving the expected output voltages. But when I connect the output of the buck converter to the input of the regulator, I am getting regulator output perfectly as 3.3V but my buck converter output is showing as some micro volts.
I think I am connecting it wrong. Please help me to connect it correctly.
Buck converter output voltage: I need 5V and 250 mA but I am getting some microvolts and microamperes.
Regulator voltage output is 3.3V but the current is reduced to 100 mA. I need at least 160 mA.