Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [lvds]

LVDS stands for Low Voltage Differential Signalling. It is a popular high-speed (>100 Mb/s) way to connect chips.

207 questions
33
votes
3 answers

Correct place to attach shields for twisted pairs

I have two PCBs connected by a cable containing 5 sub-cables: 6v power through a custom made coaxial cable (similar to that found on laptop power supplies). 2x 100mbps LVDS through 100ohm impedance screened twisted pair. 2x 1mbps CAN through the…
Rocketmagnet
  • 26,933
  • 17
  • 92
  • 177
13
votes
4 answers

LVDS vs MIPI, what's the difference?

What are the practical differences between LVDS and MIPI? A little background information: I am attempting to build my own projector on the cheap and want to use a nexus 10 LCD panel (2560 X 1600 resolution) but I have been reading mixed…
Craig Lafferty
  • 455
  • 2
  • 4
  • 8
12
votes
3 answers

Measuring impedance

I am designing and building circuits which use 100Mb/s on a Low Voltage Differential Signaling (LVDS) bus. Some of these signals need to travel between PCBs on hand made cables. The problem is that I have no way of verifying the quality of the…
Rocketmagnet
  • 26,933
  • 17
  • 92
  • 177
11
votes
1 answer

Homebrew differential 'scope probe

I may be able to get my hands on an old 600MHz LeCroy oscilloscope. However, it doesn't have any probes. Is it feasible to make an active differential probe for it using a high-speed op-amp, like the THS3201DBVT? It has a 1pF input capacitance,…
Rocketmagnet
  • 26,933
  • 17
  • 92
  • 177
10
votes
2 answers

EMI Filtering on LVDS lines

This question is slightly related to: What's radiating on my PCB? These are Beckhoff's EtherCAT industrial IO modules. Each module is connected to its neighbours by 100mbps LVDS. Each module contains an ET1200 ASIC which handles all of the…
Rocketmagnet
  • 26,933
  • 17
  • 92
  • 177
9
votes
3 answers

Via in between differential traces - how bad is it?

I'm working on a board that has some LVDS 2.5 signals. All the guides I've read about board layout say not to put vias in between the differential traces, eg this guide In a few cases it would be a lot easier to route the differential pairs out…
Alex I
  • 3,341
  • 2
  • 36
  • 59
9
votes
2 answers

Transmitting HDMI/DVI over an FPGA with no support for TMDS

I'm hoping to be able to output HDMI/DVI-D for my next FGPA project but my FPGA doesn't have native support for TMDS outputs. The FPGA is a Spartan 3E and I believe it only has support for LVDS differential signalling. I read a lot online about…
tangrs
  • 1,029
  • 2
  • 10
  • 19
7
votes
1 answer

LVDS_25 voltage range

I understand that thee voltage level for LVDS standard has a typical offset voltage of 1.25V and voltage swing of 350mV. However, when I am doing some pin mapping on Xilinx FPGA, I encountered some different LVDS standard: LVDS_25, LVDS_18…
user9870
  • 199
  • 1
  • 2
  • 12
7
votes
1 answer

Microstrip over power plane

I am designing a 4-layer PCB with 16 channels of LVDS (differential signalling, 480MHz). My layer stackup is Signal-GND-Power-Signal. A microstrip design for the LVDS channels is usually traces over a ground plane. However, I was wondering if it was…
cksa361
  • 3,814
  • 7
  • 33
  • 49
6
votes
2 answers

GND plane close to LVDS differential pair?

I have two LVDS differential pairs on my PCB, running from a connector. On the connector, I have the following sequence of nets: GND LVDS+ LVDS- GND LVDS+ LVDS- GND This is as I have seen suggested: So the GNDs pins are very close to the LVDS…
Rocketmagnet
  • 26,933
  • 17
  • 92
  • 177
6
votes
2 answers

Issue with TI comparator

I'm having trouble with a comparator from TI (LMH7322). I use it in the circuit shown in the attached image "Comparator_1". Outputs go to an FPGA. The circuit is supposed to take a single ended input signal (VG2), which is between +/- 1V at up to…
R4G9
  • 71
  • 4
5
votes
2 answers

Connecting old webcam via USB

I have removed the webcam (Chicony CNF-9157) from an old laptop with the intention of connecting it up to a computer via USB. The webcam and the LCD were connected to the motherboard by LVDS. Supposedly this webcam has a USB interface according to a…
Graham Laming
  • 179
  • 1
  • 1
  • 5
5
votes
1 answer

Difference between LVDS, MIPI, DPI and DSI

I'm on a project that involves TFT displays and Raspberry Pi Compute Module 4. I noticed that there are several acronyms, protocols confusing information. As I understand it, there are protocols: DBI: Parallel communication. It can have multiple…
Cristian Pastro
  • 135
  • 1
  • 7
5
votes
1 answer

LVDS signal distortion w.r.t switching power supply

We are using DC-DC switching regulators on board (switching freq. of regulators are ~540KHz). There is periodic noise in power/gnd at 540Khz. If we change the switching freq. of regulator, the periodic noise changes accordingly. We observe there is…
Sachin Vaish
  • 51
  • 1
5
votes
2 answers

Inner layer routing of LVDS traces in between ground vias

I have ground vias underneath an ADC on a multi-layer board for thermal relief. I am using inner layers to route the LVDS signals for the ADC. The image shows diff pairs on layer 4, which is in between plane layers. Do the ground vias have any…
JackOTrade
  • 111
  • 2
1
2 3
…
13 14