[SOLVED] Power Supply for Pic18f4550.

Hello Guys....

I m using a pic18F4550..its a 5 V microcontroller...But The current ratings for a pic18 is not specified anywhere in the data sheet....I think a 5V 500mA Power adaptor will be enough for it.If i m wrong ,plz suggest me a good power adaptor for Pic18.

Thank U....:-D

Hi,

The current ratings for a pic18 is not specified anywhere in the data sheet.

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I´m sure it is.
500mA will be sufficient for a PIC.

I think a 5V 500mA Power adaptor

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Please be sure it is within the PIC specs"absolutely maximum ratings". Especially Supply _no_load_ output voltage.

Klaus

Hi,

The basic running of the Pic only takes a few milli amps , typically around 10ma, but it depend more on what else you connect up to it, like the ASK modules or leds.
The pic chip can provide around 250-300ma maximum via its ports for things like leds though half that amount would be safer for continuous running.

Your 500ma adapter should be fine, though as Klaus just said, ensure it provides a stable 5v even at low current, sometimes the cheap adapters can pump out high voltages when used with a very light load.
If in doubt use a 9 or 12v power pack with your own in circuit 5v regulator.

Which data sheet do you have that doesn't show it's current ratings?

My PIC data sheets not only tell you their maximim ratings but how to calculate actual consumption based on clock frequency and pin loading.

Brian.

First of all Thanks for the Replay Guys....

Sorry for not reading the data sheet properly.....bit lazy to read all 400 pages.....:lol:

again Thanks all for the help.........

Praveen, there's a proliferation of cheap 5 vlt supplies, thanks to smartphones. Chop off the USB connector and connect your own crocodile pins.

Even the modest ones give a current of at least 500 ma, and the'er cheaper, more compact than rolling your own with a transformer, diode, caps and the voltage regulator.

Regards.

ard said:

Praveen, there's a proliferation of cheap 5 vlt supplies, thanks to smartphones. Chop off the USB connector and connect your own crocodile pins.

Even the modest ones give a current of at least 500 ma, and the'er cheaper, more compact than rolling your own with a transformer, diode, caps and the voltage regulator.

Regards.

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I will do that ard,,

but the problem is that my pic board consist of a very tiny 1117s regulator...The problem is, what will be the output voltage for a input 12V and 5V to the Regulator ...

Thank You..........

Praveen Kumar P S said:

I will do that ard,,

but the problem is that my pic board consist of a very tiny 1117s regulator...The problem is, what will be the output voltage for a input 12V and 5V to the Regulator ...

Thank You..........

Click to expand...

Hi,

The 1117 are rated up to 800ma but the biggest problem is the heat generated which for that chip is taken away by the copper in the circuit board, so it really depends on how a generous area they designed on your board; what make is it ?

If you see the 1117 datasheet a the minimum input voltage for a 5v output is 7v, typically you need to supply around 9v to 12v to maintain good regulation over a wide current range.

Would think the 1117 should power most of your simple projects, thought I would limit the current to 400 -500ma max or lower if the circuit board gets too warm.

THanks wp100 ....I got it............