hey,
jz wondering wat is TTL/CMOS voltage ?
n also wats a UART n USART ?
plz update me on this.. thnx

 

TTL (transistor-transistor logic) voltage is 5V for HIGH and 0V for LOW. CMOS (complementary metal oxide semiconductor) voltage is 0V for LOW and 3V for HIGH.

UART means Universal asynchronours reciever transmitter
and USART means Universal synchronous asynchronous reciever transmitter

 

Most of CMOS logic chips (e.g. CD4xxx serie) can work up to 15V supply voltage, in this case the logic HIGH +15V.

 

yes indeed the CD series can be operated over a huge range of voltages, 3V to 15V if i remember. i really like the idea that u can operate it from a 9V batt without the need for a 5V reg.

 

Wich are the transmitter receiver chip's for RS232 or RS485 communications (the serial port on your pc)