ULN2003 or buffer74LCx244?

[manju1010]

i am using pic microcontroller and i have connect 12V DC (150mA)signals to the inputs. Since, microcontroller input pins are CMOS logic and cannot sink more than 20mA so i have used ULN2003.

the 12V inputs are connected to the input of ULN and the output of ULN are connected to microcontroller input through a pull up registor.

i need isolation between 12V and microcontroller. does ULN provide any isolation??

the best solution was to use optocouplers but they are very costly.

is buffer a good solution insted of ULN?

please give your views on this.....

best regards,
Manjunath

 

[laktronics]

Hi,
Whatever ULN does is good enough, even though there is no physical isolation, your 12V will never reach the micro.
Regards,
Laktronics

 

[sabeti_1990]

hi
dependon your speed on each pin u can easily use divide your voltage by to resistor

or better way is driven a transistor by common emitter array