SN65HVD06: What is the difference between SN65HVD06 and normal RS485

Xing He

Intellectual 2025 points

Part Number: SN65HVD06
Other Parts Discussed in Thread: THVD1450

Hi Team,

The SN65HVD06 data sheet describe it as" HIGH OUTPUT RS-485 TRANSCEIVERS" , the High Output means what?

Is the differential output voltage?

If yes, Is the "High output RS-485" for some special application than normal RS485? The normal RS485 such as THVD1540 has the Vod min 1.5V and typical 3.5V, while SN65HVD06 min Vod is 2V.

Best Regards,

Xing

over 4 years ago

0 Clemens Ladisch over 4 years ago

Guru 271060 points

Yes, the SNx5HVD0x are designed to send a higher current through the bus: 1.5 V / 54 Ω ≈ 28 mA, 2.5 V / 54 Ω ≈ 46 mA. The higher current results in a higher differential voltage over the termination resistors.

The datasheet says:

They are designed for balanced data transmission and interoperate with ANSI TIA/EIA-485-A and ISO 8482E standard-compliant devices. The driver is designed to provide a differential output voltage greater than that required by these standards for increased noise margin.

For example, if there is noise that induces a current of −30 mA, the signal of a standard transmitter might be flipped, but with the SN65HVD06, there is still 16 mA left, which is enough for the receiver to detect the original signal.