I am making a college project which requires me to use a 5 V LCD display and a 3.3 V microcontroller.
I am using a 12 V power adapter to power to complete circuit.
I am using LM7805 and LM3940 to generate 5 V, and 3.3V, respectively. Is there any IC that takes in 12 V and spits out 2 or more voltage levels like 3.3 V, 5 V, 9 V etc?
If such ICs exist then what is the IC classified as? (like 7805 is a linear voltage regulator).
The IC I require should do something like this:- 
Best Answer
Using a linear regulator of any kind to get 5V from 12V is very inefficient. 3.3V is even worse. To get 0.15A at 5V (0.75W) will waste more than 1W in the regulator and will likely require at least a small heatsink. You could consider using a switching regulator.
One method that is sometimes useful is to derive 5V from the 12V with a switching regulator (or use a 5V source to begin with) and then derive the 3.3 from the 5V with a linear regulator. This works best if the current from the 5V is relatively high (for example for an LCD with backlight which might require 100mA) and the current from the 3.3V supply is relatively low (for example a typical 8-bit micro which might only require 10mA). In that case, an SOT-23 regulator could probably be used.