Hello to all,
I am currently using the MAX13487 transceiver in an RS-485 application and have observed unexpected behavior on the bus during device response. When the MAX13487 is driving the line to reply to a request, the voltage swing of the signal does not match the symmetry or characteristics of the original request. More specifically, while the request signal swings clearly in both positive and negative directions with respect to ground, the response signal appears to swing in only one direction, or significantly less in the opposite polarity.
I have attached an oscilloscope capture that illustrates this issue. The first burst is the request from the master, and the second burst is the response driven by the MAX13487. As you can see, the request exhibits full differential signaling, but the response does not.
Could you please help explain this behavior? Is this expected from the MAX13487 under certain conditions? Could it be related to fail-safe features, internal biasing, or improper bus loading?
I am also attatching the circuit snapshot.
Any guidance or clarification would be greatly appreciated.
