12V is coming from the 12V power adapterWelcome to AAC.
What is the source of the 12V input to the regulator?
How much 3.3V current is the ASM1117 supplying?ASM1117 has got burnt
I am using ASM1117 3.3V. 250mA current is supplyingHow much 3.3V current is the ASM1117 supplying?
Which version of the ASM1117 are you using?
The 3.3V version should be ASM1117-3.3.
How can we resolve this now?That means your regulator is dissipating 2.1 Watts- no wonder it's getting hot.
(12-3.3) * 0.25A
Let me correct this and check.Is there any reason why you can't go from 12V to 5V to 3.3V?
The 7805 has to convert a 7V drop (times output current) to heat, but the 3.3V regulator is being asked to convert 8.7V (times output current) to heat.
But if you feed the 3.3V regulator from the 5V rail, then you only need worry about 1.7V (times output current).
I have done this still the same issue. @metermannd said:Let me correct this and check.
I have soldered components for supply only. Issue is there only. No more components I have soldered apart from power supply right now.You can also add a power resistor in series with the 3.3V regulator input to dissipate some of the heat.
For example a 3W, 27Ω, resistor in series will drop 6.75V and dissipate 1.7W @ 250mA, leaving 0.5W to be dissipated by the regulator, which should keep it at an acceptable temperature.
Note that the resistor will get quite warm.
I have soldered components for supply only. Issue is there only. No more components I have soldered apart from power supply right now.If you cascade the 5V regulator into the 3.3V you still burn the 2 Watts, but at lease it's divided between the two parts.
The next level of efficiency (cool running) is to switch over to a switching regulator. (more expensive, noisy, but greater conversion efficiency)
By that, do you mean there is no output load on the supply?I have soldered components for supply only. Issue is there only. No more components I have soldered apart from power supply right now.
Problem is solved now. I am converting 5V to 3.3V now.By that, do you mean there is no output load on the supply?
If so, then you problem is likely a wiring mistake.
Carefully check the wiring against the schematic.
Problem is solved now. I am converting 5V to 3.3V now.If you cascade the 5V regulator into the 3.3V you still burn the 2 Watts, but at lease it's divided between the two parts.
The next level of efficiency (cool running) is to switch over to a switching regulator. (more expensive, noisy, but greater conversion efficiency)
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