# Questions tagged [lvds]

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

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### LVDS voltage levels

LVDS terminology can be a bit confusing when noted that Vcm typically is 1.2V and Vd 350mV. Does this mean 350mV as in +/-350mV so (Vin+ - Vin-) is (2*350mV) or overall swing (peak to peak of a ...
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### Formula for coupled stripline of 100 ohm

I am designing a PCB which involves MIPI and LVDS routing. What is the formula to calculate the impedance of asymmetric coupled stripline for MIPI and LVDS routing (100 ohm)? The required calculator ...
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### What is the standard common mode voltage of Media Dependent Interface MDI[0:3]± signals?

I am working on the selection RJ45 connector for MDI interface between PHY and the link-partner. I am planning to use this PHY for my SGMII interface application. From various online readings, I ...
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### What is the SGMII differential peak to peak voltage?

I am trying to understand the SGMII Driver and Receiver DC specification. Here is the link to SGMII specification - SGMII.pdf I am studying. Table-1: Driver DC specification Table-2: Receiver DC ...
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### Is it possible to convert LVDS (TI DS90c241/124) differential signals to optical signals?

I have a circuit that uses the TI DS90C241 DS90C124 serdes pair to serialize 24bits of data from one board to the other. Either due to electrical interference or the transmission media's ...
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### Interface a CML device with FPGA

I want to interface an IC with an FPGA however I noticed that the datasheet says the digital control inputs are differential and CML standard based. Can someone please guide how to interface this if I ...
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### How can I drive an LP101WX2 LCD panel with the Chalkboard Electronics HDMI-dualLDVDS converter?

I am trying to drive an LP101WX2 panel with the Chalkboard Electronics HDMI-dualLDVDS converter but all I am getting is a black screen. I tried to flash the board's firmware with both the demo and the ...
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### When can you AC couple LVDS?

According to Wikipedia Wikipedia-LVDS, 350mV signal (700mV differential) is developed when a 3.5mA current flows through 100 ohm differential resistor. and according to this app note from Analog ...
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### Passive micro LVDS cable extension

I want to extend passively a micro LVDS connection from a laptop graphic card to an lcd display panel with a 2 meter custom cable without losing image quality and flow . The connectors are male-female ...
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### What values should be checked for SGMII signal compatibility?

How can I verify the DC electrical compatibility of the SGMII signal between PHY and MAC (within FPGA)? Here is the reference-design that I am working on. Page 40 is using a Marvel PHY that is ...
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### How to connect Mini LVDS to standard LVDS or HDMI?

I've purchased a LCD TFT Display (LG Display LA123WF-SL01) that has an absurd connecter that i haven't seen anywhere online that it has been used before. The name of the connector is FH28D-64S-0.5SH. ...
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### LVDS rise/fall time measurements - confused

In a document I found they mention that the rise/fall times are measured over 20-80% of the signal. They mention that the common mode is 1.2V with a output voltage swing of 350mV. This all makes sense,...
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### Consequences of having an external signal connected to an output of a LVDS Receiver?

I am trying to debug an issue with an LVDS receiver on a fellow colleagues board. They are using an LVDS differential pair from an FPGA to control a reset line on a MPU on their board. For debugging ...
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### LVDS: Higher skew deviation or termination resistors as close as possible to the IC

I am designing a pcb with a video interface which runs lvds. LVDS has termination resistors and the datasheet states to have them put as close to the IC pins as possible. It's not 4k, but close to ...
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### Purpose of split termination in differential pairs

Can anyone tell me what the purpose of split termination is in a differential pair? If you look at the LVDS article on Wikipedia, you'll see the 100 Ohm termination resistor in parallel across the two ...
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### How can I bridge across a change in differential impedance?

In a design I'm working on, I have a 100Mbps differential signal traveling from a chip on one PCB to a chip on another PCB. For various reasons, I can't make the differential impedance the same on ...
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### One Differential end into Single Ended Input

I am trying to test a LvPECL signal into a LVDS receiver (NI 6583). Unfortunately, I currently only have the single-ended segment/connector. Looking at the spec, the single ended receiver should still ...
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### Comparator merge analog and digital grounds [closed]

My schematic looks like this: simulate this circuit – Schematic created using CircuitLab How should i connect ground and power supply to comparator? I have some signal which i want to convert ...
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### Can you integrate an LVDS with a common RS485 if the RS485 is used as a discrete and not a digital serial signal? [closed]

Is the LVDS compatible with an RS485 signal? Can i integrate 2 systems in this way?
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### Differential Signaling and RS485 difference?

I am trying to wrap my head around the difference between differential signaling (mainly LVDS and LvPECL) and RS-485. All seem like differential signaling for serial communications. From the TI Page, ...
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### Will this interface work? HCSL Clock interface

I have an HCSL interface and I want to make sure it will work correctly. The oscillator is a AX3HAF1-125MHZ part and the receiver is the NXP LS1046 device. The specs for the oscillator are: Output ...
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### Sniffing a SPI BUS

I want to sniff some data from a SPI Bus between boards from a loom machine. The bus starts at J9 from PCB 5722 and goes through 8 boards named PCB 5778, which I guess are the slaves. The connector ...
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### 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:...
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### BOE LVDS Display Troubleshooting

I am trying to bring a LVDS display up. Display: BOE EV121WXM-N10-1850. Datasheet: Link Driving MPU : STM32MP1. I am using VisionSoM STM32MP1 based evaluation Kit. Link The firmware changes required ...
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### How can I identify this QFN IC marked GX?

I'm trying to identify what this part could be based on the top marking, GX, but I've been totally unable to find it online. I'm pretty sure the packaging is QFN, it has 16 pins, and I know it has ...
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### How do terminate the coax shield of AC coupled LVDS signal? (isolated grounds)

I have an LVDS clock signal that goes to several PCB cards. Frequency: 100Hz --> 20MHz I am going to use a fan out IC to supply each card with it's own buffered CLK signal; I am not going do a '...
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### Can a laptop display directly connect with mobile phone motherboard like iPhone 4s MB. If it's possible then how can one achieve? [closed]

I have dell vastro 40 pin display and iPhone 4s MB which I want to connect directly to it. Do I have to give separate power supply to the display or will work with phone's supply and can connect with ...
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### Non white lines on 1920x180 LVDS controlled TFT

We are integrating a LVDS 27" 1920x1080 panel with a commercial DVI to LVDS controller board. We have a PC, that has a DVI output, and we connect it to the Video controller. The video controller ...
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### What is "VESA standard" PCB mounting pattern

In hirose's LVDS connector datasheet, I find there is a "PCB mounting pattern : VESA standard", but I can't find out what is special for this mounting pattern. May someone give some clues. ...
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### How to filter a LVDS clock properly

I have an LCD interface for a Beaglebone Black that is failing EMC. The Pixel clock is 65 MHz and is failing there as well as 195 MHz. Here is what the schematic looks like: The setup is 24 bits RGB ...
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### LVDS/differential driver source impedance matching

A very basic/stupid question.. I'm designing some LVDS multipoint pcbs, and I'm a bit confused about the source termination on the driver end. my colleague said that ideally there should be a 100ohm ...
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### Is there a way I can convert from USB to LVDS UART (~1Mbps)? [closed]

I'm working on a spacecraft that requires very low noise levels so it was requested that we pursue LVDS UART. So it's using something similar to RS-422 because it's differential, but instead of a ...
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### Understanding specifications

I have a differential signal which I want to measure with a differential probe. While reading the specification of the probe, I got confused with a few terms. Can someone what the highlighted terms ...
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### What are these on the probes

I am having a Lecroy differential probe and trying to measure a LVDS signal. This is the Reference Manual which I am referring to as a guide. My differential probe tip/lead model number : DX20 - SP/SI/...
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### What are the differential voltage technology used for PCIe gen 4, gen 5 and gen 6?

I have been studying various IO standards used for various PCIe generations? I understand that PCIe Gen-3 uses LVDS, LVPECL and PCML. I would like to learn what are the standards used for other ...
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### Differential Signal Measurement best practice

I have 4 differential signal pairs (LVDS Data lines and Clock) running between my Microcontroller and TFT. There are no test points over the lines. Can someone tell me what is the best practice and ...
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### LvPECL TX and LVDS RX

I have a quick sanity check question because it seems too good to be true. If I have a LvPECL signal that I want to receive, I can just use a LVDS receiver (422/485 specifically) right? From reading ...
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### Why this LVDS transceiver doesn't specify the differential input polarity?

I've been looking to implement a LVDS transceiver in my project where i can hook up to Displayport AUX differential pair. I've discovered a suitable part, SN65MLVD200A in the following design ...
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### Laptop LCD video cable extension

How long that cable: https://www.aliexpress.com/item/32885352799.html can be extended without losing image quality if I cut it in the middle and add wire? Which wire will fit and what kind is the ...
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### SPI Configuration in TFT

I have a TFT which requires SPI Communication interface to get it configured. My questions : When we say, "configure the tft", what do we actually do? Do we set some bits or erase some bits ...
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### Video format using LVDS signalling

I have a 3.1inch TFT. I have the below two pins Can someone tell me what does the 2 pins do? My questions : So, I can select either 6 bit or 8 bit for the whole communication and can't change in-...
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### Is the TMDS intended for long distance transmission?

The TMDS Transition-minimized differential signaling is similar to LVDS but not identical. I have a few questions about it: Why does it use current mode logic instead of the ubiquitous voltage mode ...
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### Power dissipation calculation for FPGA-ADC interface

An FPGA can be interfaced with an ADC using CMOS or LVDS. Is there a way to use simulation to predict the power dissipation of the I/O blocks for a given operating frequency for this interface? If so, ...
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### Level Translation Clarification (LVPECL and LVDS)

I am trying to understand something about level translation. I am sure I am probably misunderstanding something basic, so I'm hoping you can help me understand. I am trying to convert a LVPECL signal ...
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### LVDS comparator re-triggers on falling edge

I have a problem with a simple comparator circuit. The comparator takes a 1 PPS (pulse-per-second) signal as a single-ended input, and outputs an LVDS signal. The issue is that the comparator, ...
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### Common Cable/Connector with (at least) 24 parallel conductors (USB/DVI/LVDS/etc.)

I'm designing a special device that needs 24 parallel connections to the outer world. Of course compact solution is of preference. Kinda like flex cable, but it must be durable, and the end user will ...
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### LVDS difference between Vpp and Vdiff

I am looking into LVDS and I see the terms Vpp and Vdiff being used. I understand how LVDS works but the terminology is a little bit confusing. For the below picture we can see Vcm = 1.2V and the ...
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### Are eDP driver boards compatible between resolutions?

I'm looking at various eDP to HDMI controller boards that are available. The ones that I've found identify a very specific resolution: 1920x1080 or 1366x768, etc. If I buy a controller board for ...
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### Car Head Unit LCD LVDS to HDMI

I've recently picked up a head unit for my car and I am trying to get a HDMI signal to it. I've taken it apart and had a look at the hardware, and it seems to be using a single ribbon cable to drive ...
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### LVDS pairs close to other pairs

Is it a problem when I keep different LVDS traces really close to each other?
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