R1

shqihu

R1 [Copy link]

shqihu

What is the function of the network composed of R1, R2, R3 and C1 in the 100-T1 schematic? Can anyone give me an answer?

qwqwqw2088

Communication connection,

Is there any explanation other than differential RC low pass filtering?

shqihu

qwqwqw2088 posted on 2019-9-24 08:48 Communication connection, in addition to differential RC low-pass filtering, is there any other explanation?

Can you explain in detail how the parameter value is determined?

qwqwqw2088

shqihu posted on 2019-9-24 20:46 Can you explain the function in detail and how the parameter value is determined?

From the partial circuit provided by the original poster, it should be some kind of communication line transmission, there should be some protocol rules, but the original poster did not explain

In order to make the signal transmission of the bus reliable, RC networks are added to all signal lines on the bus to achieve optimal signal transmission.

Adding RC is to filter out noise interference

shqihu

qwqwqw2088 posted on 2019-9-25 09:21 From the partial circuit provided by the OP, it should be some communication line transmission, there should be protocol rules, the OP did not explain in order to make the bus signal transmission...

Sorry, I didn't write it clearly. This circuit is a 100BASE-T1 (vehicle Ethernet) interface with a rate of 100Mbit/s. The circuit before the common-mode inductor is indeed a noise removal circuit and needs to be connected to a twisted pair. But I don't know how to determine the values of the resistors and capacitors.

xiaxingxing

qwqwqw2088 posted on 2019-9-25 09:21 From the partial circuit provided by the OP, it should be some communication line transmission, there should be protocol rules, the OP did not explain in order to make the bus signal transmission...

RC low-pass filtering, why does C1 need to be connected in parallel with such a large (100K) resistor?