TTL o/p or CMOS o/p for different Vcc

[Eric Koh]

Hi...does anyone know that If I power up the uController with 3.5V or 5V, will the o/p's have different levels of High?

Seems that a lower operating voltage appears to lower the max operating frequency of the PIC as well...

 

[Nigel Goodwin]

Hi...does anyone know that If I power up the uController with 3.5V or 5V, will the o/p's have different levels of High?

Of course it will, the outputs switch from 0V to the positive supply (actually not reaching either rail) - if you use a 3.5V supply your output can't go above that.

 

[TKS]

mhh..

soow the minimum supply voltage should be a 2,5 volts

because else it cant sense a hihg port..??

or is this wrong..should it be 3volts..??

TKS

 

[Exo]

Re: mhh..

soow the minimum supply voltage should be a 2,5 volts

because else it cant sense a hihg port..??

or is this wrong..should it be 3volts..??

TKS

Depends on the pic in question, look at the datasheet for the pic you want to use. Most of 'em are 3V min. but there are lot's wich will go lower