u can not give 9 V directly | Microcontroller › 8051 › at89c51 problems help me :'( › u can not give 9 V directly September 1, 2015 at 10:22 am #13247 Ashutosh BhattParticipant u can not give 9 V directly to micro controller. it will certainly burn it. micro controller works on 5 V supply only
