RS232 to TTL/CMOS Interface Converter


The ic232TTL converts RS-232 to TTL/CMOS compatible level. Two channels are used to convert from RS-232 to 0/+5 VDC signals, and two channels are used to convert from 0/+5 VDC signals to RS-232. Therefore, this converter supports TD, RD, RTS, and CTS. The RS-232 side is a DB9 female connector while the TTL/CMOS side is a DB9 male connector. This unit is powered from the RS-232 data and handshake lines whether the lines are high or low and may work at baud rates up to 115.2kbps. The handshaking lines (pins 7[RTS] and 4[DTR]) may be in either a high or low condition, but must be present to power the converter. It is important that TTL/CMOS logic, and only TTL/CMOS logic (0 to +5 VDC) be used for the TTL/CMOS side of the converter. The maximum sinking current for one TTL/CMOS output is 3.2 mA. The maximum source current for one TTL/CMOS is 1 mA. Signal levels are inverted by the converter.


  • Electrically converters ASYNC RS-232 to TTL/CMOS level
  • Interface powered, no external DC power required for this converter
  • RS-232 DB9F connects
  • TTL/CMOS level connects directly to embedded system’s UART
  • Baud rate up to 115.2k