RS232 request

peiyq

Expert 1400 points

Other Parts Discussed in Thread: TRS3122E

Hi TI，

would you please recommend a solution ，we want to convert UART which the level is 1.8V to 12V RS232

thanks

B&R

peiyuanqing

over 6 years ago

0 Miguel Robertson over 6 years ago

TI__Guru 62920 points

Hello,

I'd recommend the TRS3122E device for this application. It can be powered via 1.8 V and provides two channels of conversion from UART to RS-232 and from RS-232 to UART (assuming the UART is using 1.8 V logic signaling). Will this work for your application?

You could also consider TRS3253 if more channels are needed (in this case, the device has three transmitters and five receivers). This device would require either a 3.3-V or 5-V power supply, but would still be compatible with 1.8-V logic signals.

Regards,
Max

0 peiyq over 6 years ago in reply to Miguel Robertson

Expert 1400 points

Hi Max，
thanks for your quickly support，would you please check it can support 12V RS232， or it need other level shift convert 5.5V to 12V？
B&R
peiyuanqing

0 Miguel Robertson over 6 years ago in reply to peiyq

TI__Guru 62920 points

Yes, TRS3122E will support high-voltage RS-232 signaling directly and would not require additional level shifters.

Max

0 peiyq over 6 years ago in reply to Miguel Robertson

Expert 1400 points

Hi Quote，

in datasheet， i have no idea how to do a 1.8V to ±12V，could you give a schematic for reference

B&R

peiyuanqing

0 Miguel Robertson over 6 years ago in reply to peiyq

TI__Guru 62920 points

You can reference Figure 13 in the datasheet for an example implementation. The DIN and ROUT pins are the 1.8-V data (in this case, going to an MCU) and the DOUT and RIN pins would connect to the RS-232 interface.

Regards,
Max

0 peiyq over 6 years ago in reply to Miguel Robertson

Expert 1400 points

Hi Max,

got you,we can do schematic now ,another question is how to config TRS3122E let the DOUT and RIN worked in 12V ?

thanks

B&R

peiyuanqing

0 Miguel Robertson over 6 years ago in reply to peiyq

TI__Guru 62920 points

The device is designed specifically to support RS-232 on the DOUT and RIN pins, so no configuration is needed - this is the way the device always operates. You should make sure to follow the example diagrams in the datasheet including the C1/C2/C2/C4/C5 connections, though. These capacitors are used as part of a charge pump circuit that is needed to take the 1.8-V supply voltage and use it to generate the higher-voltage positive and negative voltage references needed for the RS-232 interface.

Regards,
Max

0 peiyq over 6 years ago in reply to Miguel Robertson

Expert 1400 points

nile_RS232(TI).pdf

0 peiyq over 6 years ago in reply to peiyq

Expert 1400 points

3348.nile_RS232(TI).pdfHi Max,

would you please review our schematic ?

thanks

B&R

peiyuanqing

0 Miguel Robertson over 6 years ago in reply to peiyq

TI__Guru 62920 points

This schematic looks good to me. I would recommend tying the unused DIN port high or low, though, since this can reduce current consumption and prevent toggling due to noise. Also, if there are no other components that require 3.3 V, you could eliminate the 3.3-V regulator and power TRS3122E solely via 1.8 V.

Regards,
Max

Power management

Power management forum

RS232 request