RS-232 Modem Interface Module for Protection Relay, IED, and Substation Automation Reference Design


Design files


The TIDA-00557 reference design provides an interface for a true RS-232 (eight signal + ground) physical layer interface for data terminal equipment (DTE) using a DB-9 plug-type connector with a provision for a data communication equipment (DCE) interface. This is intended for smart grid IED’s, protection relays and substation automation segments. This design meets +-/ 8kV contact discharge ESD protection as per IEC61000-4-2 and +/-1kV surge protection as per IEC61000-4-5.

  • Demonstrated Modem Control Hardware using RS232 with 2,4 and 8- wire interface
  • Provide DTE /DCE Interface with  DB-9 connector
  • Baud Rate 1200, 2400, 4800, 9600, 19200-115200bps
  • SN6501 transformer driver  based Isolated output
  • Galvanic Isolation by Digital isolators with options of 2, 4 and 8 Wire interface
  • Operates with Single 5V input
  • ESD IEC61000-4-2 +/- 8kV Contact Discharge
  • Surge IEC61000-4-5 +/- 1.0kV
??image.gallery.download_en_US?? View video with transcript Video

A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.


Detailed schematic diagram for design layout and components


Complete listing of design components, reference designators, and manufacturers/part numbers


Detailed overview of design layout for component placement

TIDRFF1.ZIP (5162 K)

Files used for 3D models or 2D drawings of IC components


Design file that contains information on physical board layer of design PCB

TIDRFF0.PDF (3138 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Digital isolators

ISO7321CLow-power, dual-channel, 1/1, 25-Mbps digital isolator

Data sheet: PDF | HTML
Digital isolators

ISO7341CLow-power, quad-channel, 3/1, 25-Mbps digital isolator

Data sheet: PDF | HTML
RS-232 transceivers

TRS3243E3- to 5.5-V multichannel 500kbps RS-232 line driver/receiver with +/-15-kV IEC-ESD protection

Data sheet: PDF | HTML
RS-232 transceivers

TRSF3238E3- to 5.5-V multichannel 1Mbps RS-232 line driver/receiver with +/-15-kV IEC-ESD protection

Data sheet: PDF
Transformer drivers

SN6501Low-noise, 350-mA, 410-kHz transformer driver for isolated power supplies

Data sheet: PDF | HTML

Technical documentation

= Top documentation selected by TI
No results found. Please clear your search and try again.
View all 1
Type Title Date
* User guide Digitally Isolated, RS-232 Interface Module With Handshake Signals Design Guide (Rev. A) Jul. 13, 2015

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​