The single-ended signal is relative to the differential signal. The single-ended input means that the signal has a reference terminal and a signal terminal. The reference terminal is generally the ground terminal.
Differential transmission is a signal transmission technology, which is different from the traditional practice of one signal line and one ground line (single-ended signal). Differential transmission transmits signals on both lines, and the amplitudes of the two signals are equal. Phase opposite. The signals transmitted on these two wires are differential signals.
Compared with the practice of single-ended signal routing, the advantages and disadvantages of differential signals are
advantage:
1. Strong anti-interference ability. Interfering noise is generally equal and loaded onto the two signal lines at the same time, and the difference is 0, that is, the noise has no influence on the logical meaning of the signal.
2. The magnitudes of the coupled electromagnetic fields between the lines are also equal, and their signal polarities are opposite, and their electromagnetic fields will cancel each other out. Therefore, it can effectively suppress electromagnetic interference (EMI) to the external electromagnetic. Since the two lines are very close together and the signal amplitudes are equal, the interference between the two lines and the ground is also small.
3. Timing positioning is accurate. The receiving end of the differential signal is the point at which the difference between the signal amplitudes on the two lines changes positively and negatively, and is used as the point at which the logic 0/1 transition is judged. Ordinary single-ended signals use the threshold voltage as the transition point of the signal logic 0/1, which is greatly affected by the ratio of the threshold voltage to the signal amplitude voltage, and is not suitable for low-amplitude signals.
shortcoming:
If the area of the circuit board is very tight, the single-ended signal can have only one signal line, and the ground line must go to the ground plane, while the differential signal must go to two lines of equal length, equal width, close proximity, and on the same level. This situation often occurs when the pin spacing of the chip is so small that only one trace can pass through it.
1. Basic difference
Don’t talk about theoretical definitions, but practical ones. A single-ended signal refers to a signal transmitted by one line. How can a line have a signal without a reference point? easy, the reference point is the ground. That is to say, a single-ended signal is the level difference between the transmission on one wire and the ground. Then when you transmit the signal from point A to point B, there is a premise that the ground potential of point A and point B should be almost the same.
A differential signal refers to a signal transmitted by two wires, and the transmission is the level difference between the two signals. When you transmit the signal from point A to point B, the ground potential of point A and point B can be the same or different, but the ground potential difference between point A and point B has a range, beyond which there will be problems .
Shenzhen Zhongling Technology, as a supplier of hub servo motors and drives, single-ended drives and differential drives are also selling well at home and abroad.
Post time: Sep-05-2023