I need some help in making Good power stability circuit

[aman00007]

I have one lora rfm95w one atmega644p and one rtc and my battery voltage is 8v for atmega 644 need 5v rtc need 5v and lora rfm 95w need 3.3v how I make good circuit so that less power consumption and industrial grade pls help me for making my circuit

 

[danadak]

lora rfm 95w

That module only needs 100 mA, why do you say 95 W ?

 

[aman00007]

Yes

That module only needs 100 mA, why do you say 95 W ?

It's module name rfm95w

It's module name rfm95w

Can you make circuit for this

 

[danadak]

If you are not totally focused on power savings just use two 3 terminal regulators
for the correct voltages needed.

If power conscious use dual switching regulator where 5V comes from switcher
and its internal LDO used to gen the 3.3V

https://www.mouser.com/c/semiconductors/power-management-ics/voltage-regulators-voltage-controllers/switching-voltage-regulators/?number%20of%20outputs=2%20Output&topology=Buck

Just an example (this has to be designed for your 8V input) : https://www.analog.com/media/en/technical-documentation/data-sheets/3645f.pdf

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Note you can always use just a single buck and an external LDO to do same thing.
Probably cheaper than above example.

Or in simplest form use 2 zener diode shunt regulators, but they waste a lot of power.

 

[Taj bartlem]

DC-DC buck convertor, Zener diode, open loop regulator, closed loop regulator or 3 pin voltage regulators(78** and 79**)

 

[Harald Kapp]

Ready to use step-down switching regulators are readily available from many (Asian) vendors.
There are also plug-in replacements for teh venerable 7805 regulators using swithc-mode technology, although these tend to be more expensive than the cheap modules from Asia.