EVAL232R Datasheet, PDF (15/18 Pages) Future Technology Devices International Ltd. – FT232RL USB to RS232 Evaluation Module

7. Module Circuit Schematic
Page 15
Figure 5 shows the EVAL232R circuit schematic. For the EVAL232R the FT232RL has been used to make a USB to
RS232 converter. A TTL – RS232 Level Converter I.C. is used on the serial UART of the FT232RL to make the RS232
level conversion. This, for example can be done using the popular “213” series of TTL to RS232 level converters.
These devices have 4 transmitters and 5 receivers in a 28-LD SSOP package and feature an in-built voltage converter
to convert the 5V (nominal) VCC to the +/- 9 volts required by RS232. An important feature of these devices is the SD
pin which can power down the device to a low quiescent current during USB suspend mode.
The RS232 level converter device used on the EVAL232R is a Zywyn ZT213LFEA which is capable of RS232
communication at up to 1Megabaud baud.
In the EVAL232R CBUS0 and CBUS1 have been configured as TXLED# and RXLED#, and are being used to drive
two LEDs which indicate transmission and reception of data.
EVAL232R FT232RL USB to RS232 Evaluation Module Datasheet Version 0.90
© Future Technology Devices International Ltd. 2005