Hi,
I'm using the ISL3259E RS485 transceiver and I'm getting a bit error when changing from transmit enable to receive enable. Following the change on the RE/DE pin a bit the RO line goes from high to low (start bit condition). The RS485 line is terminated but not being driven by another devices (also tried with another device on the bus). The RE/DE pins are tied together so are transitioning at the same time.
The attached images shows the issue. The bus is terminated but not driven by any other devices.
The traces are connected to the following nets:
pink: DE/RE
blue: RS485 bus (differential probe A-B)
yellow: RO
It looks to me that The transceiver is briefly in transmit and receive at the same time.
Any insight or ways of preventing this erroneous falling edge would be appreciated.
Jack
Hi Jack,
To best support you on this you will need to submit a Technical Support ticket by going to our support portal from the following link: https://en-support.renesas.com
You will need to sign in with your company email address, and if you don't have an account you will need to register with one. https://www.renesas.com/register
Please provide complete schematic showing this part and all the connections and surrounding parts when you submit your request. The factory apps team who supports this product will require this.
Best regards, Cindy, Renesas Online Applications Support Engineer