4
votes
Accepted
A TVS for lightning surge protection
A TVS diode is probably not going to be enough to protect your equipment from a surge caused by lightning. Generally you'll want to use gas discharge tubes to take the brunt of the surge, then either ...
- 21.8k
4
votes
What's the difference between long and short (physical shape) type of RJ45 connector of the same specifications?
Just the body length after the socket connection where the rj45 plugs in.
This will likely affect the pin pattern for soldering to the board and the securing tags or pins.
- 6,954
4
votes
Accepted
How does an ethernet controller work?
Start with reviewing the OSI model. The part of this 7-layer burrito you're probably wondering about is Layer 1, the Physical layer or PHY.
Essentially, the Data Link Layer (DLL, Layer 2) connects to ...
- 63.8k
3
votes
Wiznet W5500 RSVD pins
Unlike pin 7 that explicitly states this: -
You can reasonably assume that pins 38 to 42 can either be NC or connected to a pull-down resistor.
- 501k
3
votes
Accepted
Interfacing RJ45 to 3 pin RMII and bidirectionality
That PHY is for 100BASE-T1 (commonly known as "Automotive Ethernet" or BroadR-Reach), which is different from "standard" 100BASE-TX (FastEthernet) in that it uses a single pair for ...
- 5,820
3
votes
SFP, understanding control pins
My question is, when the SFP device first turns on do I need to toggle the TX_DISABLE (LOW is on, HIGH is off) before first using it?
Not for any SFP module I'm familiar with. Some require an I2C ...
- 135k
3
votes
Accepted
Why does the 10G XGMII specification mention a 32b instead of 64b bus for 156.25MHz?
It's supposed to be a 32 bit DDR bus (well, 36 bit as it is 32 data plus 4 control). So the clock is 156.25 MHz (10G/64), and both edges are used, so that gives you 312.5 MT/s. See IEEE 802.3 46.3.1.3:...
- 41.8k
2
votes
Can we do source transformation for dependent sources?
Yes, source transformation can be carried out for dependent sources much the same way for independent ones. Here right and left circuits are equivalent and can be used interchangeably.
- 1,901
2
votes
Accepted
How to code communication between two enc28j60?
It is up to you to decide if IP/TCP/UDP makes sense. You know what the purpose of these protocols is, right: communicating on very, very large scale networks, composed of very different kind of ...
- 16.4k
1
vote
What's the difference between long and short (physical shape) type of RJ45 connector of the same specifications?
The bel fuse has a common mode filter on the input, other than that the specs are mostly the same. The bel-fuse is about half the cost of the wurth integrated jack.
Source: https://www.belfuse.com/...
- 93.2k
1
vote
Accepted
Connecting two W5500 via UDP results in PHY link off
Are you connecting the boards directly to each other or via a network switch?
W5500 does not support auto MDIX so you may have to use a crossover cable if you connect the boards directly.
I recommend ...
- 9,166
1
vote
Physical interface for ADSL Annex J
ADSL is AC coupled and thus can tolerate some forms of glavanic isolation.
The old "splitter" boxes put the DSL signal onto the existing (DC voltage when idle) analog/ISDN lines via ...
- 10.7k
1
vote
How Nic process packets
If you want minute detail, then it might be worth looking at various ethernet mac implementations for fpgas.
eg: https://github.com/yol/ethernet_mac
you could also check out opencores.org
XMOS also ...
- 7,105
1
vote
Interfacing RJ45 to 3 pin RMII and bidirectionality
The board has an automotive 100Base-T1 Ethernet interface which uses a single bidirectional pair. It is not RMII and it is not compatible with anything else than other 100Base-T1 devices. It is not ...
- 196k
1
vote
W5500 network configuration issues
Let me express my thoughts on the case. It is not complete answer as details are not enough, but hopefully will give a direction for further investigation.
Not clear if the problem is PHY circuitry ...
- 7,264
1
vote
KSZ8895 Switch-Circuit Problem
You should read the datasheet for the strapping and configuration pin options. I'm not sure whether they all float to a valid configuration (particularly SCONF0, SCONF1, PS0, PS1 and obviously ...
- 3,801
1
vote
Difference between Hz and bps
Lets assume that you have two frequencies f1 and f2 and f1 represents 0 and f2 represents 1. Further assume that you need at least a separation of delta between the two frequencies so that they do not ...
- 179
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