I've been trying to make a voltage regulator using a zener diode.
I used the BZX79 3.3V Zener diode. I connected the diode as the following:
Data Sheet. I assumed that as as most of them it operates at around 1mA to 10mA safely in the break down region.
I connected my supply which was 5V. The resistance was chosen to be 220 ohms. This will make the max current of the zener around 7mA. Which should be safe.
Now, when the zener was unloaded, I got a smooth 3.3V as an output.
But, when I loaded the zener diode, the voltage across the diode dropped to 2.4V.
Why did that happen?
My assumption is the following:
The load which should operate at 3.3V, is consuming way too much current that the zener current is below the min current. This caused the zener to get out of the break down region.
Is my deduction correct? And what are available solutions, taking in note that I've used probably the smallest resistance possible that is 220 ohms. (At least of what I have).
I also have a supply of 8.4V. Will it work if I connected it directly to the supply? At the end I will have more current available to the zener even after loading it.
The data sheet states that the zener is fine for 6 Amps. That is a huge and weird number isn't it?