I have the need of a USB-TTL converter cable, but all I have is a USB-FTDI converter cable
FTDI is just the brand of the manufacturer, both cables that you shown do the same thing.
What you describe as USB-FTDI is a USB-TTL converter
The USB TTL Serial cables are a range of USB to serial converter cables which provide connectivity between USB and serial UART interfaces. A range of cables are available offering connectivity at 5V, 3.3V or user specified signal levels with various connector interfaces.
All cables feature an FTDI FT232R device integrated within the cable USB type ‘A’ connector, which provide access to UART Transmit (Tx), Receive (Rx), RTS#, CTS#, VCC (5V) and GND connections. All cables are fully RoHS compliant and are FCC/CE approved.
The use of RTS (Request to Send) and CTS (Clear to Send) handshaking depends on the specific implementation and the way you'll use the cable in your project.