i am doing a project to convert usb to rs232, rs422 and rs485.for this i am using ft232rq for usb uart interface, adm3251e for rs232 transciever and adm2490e for rs422/rs485 transciever.my question is, is it possible for ft232rq to drive these 3 transciever at a time..the dc supply current for ft232rq is 15mA and output dc current is 24mA and the bus power supply is 90mA.

 

You're not going to be able to do all three simultaneously, as you'll wind up with conflicting signals.

You'd have to use some type of bus interface so just one pair of protocols was active at any one given time.

 

thank you for ur reply but how to make bus interface?please help me.

 

finally i'm using dip switch for switching signal to rs232, rs422 and rs485 drivers and using AND gate at the output of reciever.is there any better idea??