SN65HVD1050: Over shoot Bus signals

user5163865

Part Number: SN65HVD1050

Hi,

The customer has been using SN65HVD1050 for a long time and found that the voltage on the Bus side was overshooting.
Do you know the cause of the overshoot?

I attached the material, so please refer to the circuit diagram and measurement results.

Q1: The first overshoot (0.5V) in Fig. 4 occurs with a probability of about 10%.
Q2: The final overshoot in Fig.4 always occurs.
I don't know the cause, so could you give me some advice?

Regards,
Hiroshi

over 4 years ago

0 Clemens Ladisch over 4 years ago

Guru 318700 points

This typically happens when two or more drivers are active at the same time.

When two devices try to transmit at the same time, the device that sees a dominant bit when it is actually sending a recessive bit knows that there is a conflict with another device with higher priority, and stops. Every frame starts with the sender's ID, so such a conflict is resolved after a few bits.

The ACK bit at the end of a frame is driven by all devices that have received the frame.

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SN65HVD1050: Over shoot Bus signals