The FT232RL USB to TTL 3.3V/5V FTDI Serial Adapter Module is a popular module that is used to connect a TTL serial communicating device to a PC via a USB mini port. This converter module has options for different output voltage options which are set by the jumper on the board.
 
Features and Specifications of FT232RL USB TO TTL Converter
 
Operating Voltage: 5V/3.3V DC
Max Current Draw: 5V - 500mA; 3.3V - 50mA
Connector: Mini USB
Fully integrated 1024 bit EEPROM storing device descriptors and CBUS I/O configuration
Data transfer rates from 300 baud to 3 Mbaud (RS422, RS485, RS232) at TTL levels
128 byte receive buffer and 256 bytes transmit buffer
Transmit and receive LED drive signals
Fully integrated clock generation with no external crystal required