SN65C1168E: SN65C1168E RS transceiver is properly setup, no output

To enable the device, what voltage level should be applied to pin 4, the enable line.

Hi Jordan,

Thanks for reaching out on E2E!

The driver enable pin DE requires a minimum of 2V. I would probe this pin on the transceiver to confirm if the drivers are enabled.

If you are still having issues, can you share a waveform of one of the RS485 Y/Z pairs and the corresponding D input (if possible also the DE line)?

I would also doublecheck that your RS-485 driver/receiver lines aren't mixed up. 

Did the transceiver previously work, or is this a first time setup?

Best,

Ethan

Hello Ethan,

This is a new PCB design and the first use of this particular IC. The enable line is 3.3V from a uProcessor. I have looked at these with the scope,  I will setup the Oscope and get a capture for a timing check. 

I am trying to look at what else may not be setup correctly. Any other thoughts?

I have used lots of similar devices in the past. I have tried testing this on a few PCB's.

How about the statement below about the enable input, the test condition was Vcc, 5V.

Thanks,

Jordan

Hi Jordan, 

For that screenshot, VCC is tested as an upper limit for the current spec, but 2V is still the threshold. 3.3V will be just fine for the enable pins. 

I would also double check the driver input voltages to make sure they are valid low/high values (above 2V or below 0.8V). Again, if you can include the driver input signal in your waveform along with the individual differential outputs, this would be helpful.

Can you also provide an image of the top marking of the device and where you sourced it from?

Best,

Ethan

Hello Ethan,

The is a project that requires part traceability; they likely were ordered from digikey. There is nothing on any of the outputs... I am going to try receiving Monday.

Thanks,  Jordan

Enable and data toggling in sync