Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [signal-integrity]

Questions regarding how to properly ensure Signal Integrity, protection from noise, shielding, proper pcb layout.

1
vote
0answers
22 views

Signal Attenuation TVS and series resistor

This question is in regards to signal attenuation on high speed data lines like RS-485 (and any others as well). I'm new to the signal world, so please bear with me here. Are there some useful ...
0
votes
1answer
34 views

Boosting the Analogue Response of a Sensor

I have a A1308KUATN-9-T Hall Effect sensor with the following sensitivity (from the data sheet): As you can see, the sensitivity comes to about 9mV per Gauss on average. My calculations (see below ...
3
votes
1answer
115 views

Analogue (or digital) signal integrity with multiple sources of noise

tldr: Can I transmit an analog signal through a noisy environment without it being corrupted, or should I use a digital signal instead? My requirement is to transmit a signal from a MA3 absolute ...
0
votes
1answer
29 views

Digital signal integrity & grounding

I have a battery operated device with an old B&W LCD in it. I'm tapping to the display bus and would like to input it into an FPGA for some processing. The bus includes vertical and horizontal ...
0
votes
3answers
65 views

Tektronix function generator THD

I am confused by the datasheet of the AFG3021C: https://www.tek.com/link-click-count?nid=75006&url=https%3A//download.tek.com/datasheet/AFG3000C-Arbitrary-Function-Generator-Datasheet-75W282817....
0
votes
0answers
37 views

Does the location matter when performing unbalanced to balanced source conversion for this scenario?

Below circuit shows the issue when the output impedance of a DC-like source V is not balanced when coupled to a Diff Input(differential input of a data-acquisition board). As you see as an example for ...
0
votes
0answers
53 views

How do passive boosters/repeaters (such as a HDMI 'booster') work?

I have a HDMI device and I want to connect it to something very far away. I notice you can buy a HDMI booster to do this, but some of them are unpowered (they take no external power). How can a signal ...
8
votes
3answers
812 views

If temperature is not an issue, what can be said about the different ceramic dielectrics

Let’s assume we have a circuit whose operating ambient temperature range is well-regulated to 25+-5C. Besides cost, what would be the use cases for the different ceramic dielectric types? In other ...
3
votes
1answer
87 views

JTAG trace length affecting programming ability

I've recently had a design made that requires a programming port to be located quite far from the device I'm trying to program. This has meant that my cJTAG traces are around 13cm long. I think as a ...
1
vote
1answer
62 views

I2C bus line over different layers in an arc

I have the following board design in mind: It's a 4 layer, ~5cm diameter board where 10 slave PCB's will be soldered to it that are connected over the I2C bus. The trace line you see is roughly 8 cm ...
0
votes
1answer
42 views

Are digital inputs of data acquisition devices differential or single ended?

I read that in almost all daq board datasheets the analog inputs are specified as single ended or differential inputs. But the same daq have digital I/O ports. How can one understand whether the ...
1
vote
0answers
63 views

Reducing electromagnetic interference in underwater acoustics cables

Our college underwater robotics team has a passive acoustics system with four hydrophones that provide an analog signal typically between +/- 200 mV corresponding to the sound wave at that point in ...
2
votes
1answer
169 views

Grounding and Signal Integrity of my PCB Layout (ADC, SMPS, SD card, USB)

I am currently designing a battery monitoring system for an 8 cell lithium battery pack. I originally made the device using a STM32 dev board and breadboard, with an SD card to log data. The system ...
1
vote
2answers
143 views

Advice for 25-50 Mbit SPI lines - PCB design

I would like to ask some advice for my layout design. I am working on a layout design. The designed PCB will be a Beaglebone Black (BBB) extension card. It is a four layer PCB with the following ...
0
votes
0answers
30 views

Coupling differential line to a single ended daq

Sorry for the primitive drawing but it was for clarity of the question: If a differential balanced signal will be conveyed to a single ended inputs of a DAQ, what would be the proper connection? ...
1
vote
1answer
106 views

Locating pairs on an LVDS cable

For a 2-row connector intended to interface a cable to a PCB, which method is preferable for twisted pair LVDS signals? Horizontal Pairs: LVDS1-    LVDS1+    ...
1
vote
1answer
79 views

PH Probe Unstable Measurement

I've recently set up a small circuit for PH measurement using a BNC PH electrode. A picture of my circuit can be seen below: The linear reference REF1 alongside opamp U1A serve to generate a 2.5V ...
2
votes
2answers
229 views

SPI bus multi-slave termination

I have been using a Tiva C microcontroller (TM4C1294NCPDT) as master to communicate with 6 SPI devices (slaves). The SPI clock is 8 MHz with 1.5 ns rise time. My idea is depicted bellow. My design do ...
0
votes
1answer
81 views

How to use 0.1 inch header footprint for high speed signals?

I have a board which has a dual 0.1 inch header footprint (the totally standard kind you see everywhere). Trouble is, this carries a fast 300-500 Mbit DDR LVDS signal (!!) to another board. Okay, so ...
8
votes
4answers
2k views

Understanding the Maximum Speed that can be Transmitted over a Cable

I am trying to source a FFC/FPC cable for USB3.0 (+5gbps). This brought me to the question of signal transmission. I'm somewhat of a beginner in this topic. I know that you should match impedance on ...
0
votes
1answer
101 views

Is this alternator W RPM input circuit ok and how can I improve it?

I need a robust and reliable way of taking a RPM signal from the W terminal of a standard automotive alternator. Most of the time the signal will come from a 12V alternator but there is a requirement ...
0
votes
1answer
65 views

Difference between conventional Eye-diagram voltage plot and “Eye-density” plot in ADS Keysight Simulation

I know what is eye diagram. It is the sampled voltage plot at the clock frequency (Usually) of my circuit and superimposed. If the logic 0 corresponds ...
0
votes
4answers
58 views

Single voltage power supply to +/- rails

I have a wall wart coming into my circuit in the DC barrel jack shown in the picture. I want to have a positive and negative rail for my op amps as I am unsure of the effect of biasing my signal lines....
1
vote
1answer
82 views

Gounding for EMI and signal integrity - LED Matrix multiboard design

I would like to implement a LED Matrix circuit like this one, where the LED matrix enclosed within the blue dots will be on a seperate PCB than the rest of the circuit. Since this will be a ...
1
vote
1answer
82 views

How to route a nasty signal (200V/µs)?

I have to route this signal for a distance of ~70mm† through a dense (mostly digital) 2-sided board. The signal is generated externally and I have no control over its shape, it's basically a pulse ...
0
votes
2answers
162 views

What does it mean if eye diagram voltage (0 and 1 level) goes negative?

I have created a differential channel and was testing the channel with simple testbench to check the eye diagram. Now I know the channel performance is very bad (It of several PCB transmission lines, ...
1
vote
2answers
119 views

High Speed Signal on Large Circular Ring

It's frequently communicated that when working with signals in the Ghz range, routing is extremely important to signal integrity. Pretty much any inclusion of unnecessary stubs is out of the question, ...
0
votes
1answer
65 views

Connecting LVDS signal from one PCB to another

I am tryin to connect LVDS signals on one PCB to another. I am using an FFC cable and am trying to understand if signal integrity would become an issue. The shortest FFC cable that I could find is ...
0
votes
0answers
42 views

Remote triggering by using optoisolators

I need to hardware-trigger three modules from a pulse signal source. According to their data-sheet each module requires between 5 to 15V for trigger high and 0 to 5V for low. Each module draw around ...
0
votes
2answers
53 views

Understanding a common mode signal conditioning module

As far as I understand, normally an ideal differential amplifier(or an instrumentation amp) can reject common mode(CM) voltages up to around its rail voltages. Let's say the rails of the diff. amp ...
1
vote
4answers
390 views

Effect of cable capacitance to low frequency analog voltage signal transmission

Regarding sending a low freq. (<150Hz) analog voltage signal with CAT6 STP cable I have heard that: if the frequencies down the cable will be low, there may be an issue with it driving a capacitive ...
1
vote
5answers
109 views

Sensor question for low freq

A floating DC voltage output sensor will be powered locally and the signal will be sent outdoors 200 meters far away to a data acquisition board. I didn't receive the sensor yet and don't have the ...
1
vote
1answer
32 views

Output impedance imbalance and CM noise in truly floating sources

In the following Figure 1 and Figure 2, the sensor is the one in dashed box. The output impedance of the sensor is big and in this case is 1k Ohm. And as you see regardless of the sensors are bipolar ...
1
vote
1answer
27 views

Comparison of two configurations to balance source impedance

This is a generic question for about frequency sensors. But as an example I use this sensor which has around 1k output impedance. So in below drawing the source in dashed box has 1k output impedance: ...
0
votes
3answers
100 views

Should a trace be connected through multiple pins on a pin header?

I'm designing a modular board, where the two modules are connected through pin headers. For mechanical stability I have more pins than traces and my question is that which is the better: route each ...
2
votes
1answer
114 views

Why doesn't smaller Transmission Lines affect Signal Integrity? [duplicate]

I am reading High Speed Digital Design: A Handbook of Black Magic. It was mentioned that if length of transmission line (Microstrip or stripline) is less than 1/...
0
votes
2answers
223 views

Multiboard Grounding In High Frequency

How can ground loop be avoided when connecting two system with same ground. This happen in PC whith SATA cable or PCIe Card with seprated power cable. My System Board: I have two pcb each with a ...
1
vote
2answers
57 views

Signal Integrity

I am working on signal integrity of the PCBs. I have some misunderstanding in handling High frequency signals. Resistance and Inductance increases with high frequency signals. so we have to take while ...
6
votes
2answers
1k views

Ethernet RMII on two layer PCB

INTRODUCTION: I'm aiming to design an Ethernet connected system as a hobby ( ie. plenty of time but not wishing to spend much ). My design constraints would ideally be sticking to a 2 layer 100mm x ...
0
votes
4answers
129 views

How should I connect my PCBs? [closed]

I will need to connect several PCBs within a single enclosure for the project I am working on (They are split to reduce cost should there be a manufacturing error). I need to connect an I2C Bus, 5V , ...
0
votes
1answer
39 views

If two iBeacons are too close to eachother, could their signals get confused for one another?

I have a simple question that I can't find the answer to. I am testing an app with some iBeacons, and I observe that one of my iBeacons never begins to range...the region is monitored, its just not ...
0
votes
1answer
183 views

Connecting two USB 2.0 devices to a single USB port on an MCU

I'm designing a PCB where I need to have two possible USB 2.0 connectors (and hence 2 sets of diff pairs) connect to a single USB 2.0 port on an MCU. Only a single connector would be used at any given ...
0
votes
2answers
94 views

The probe and Oscilloscope selections for measurement

*I searched about the correct oscilloscope and probe to measure the a signal with a certain frequency. I read some documents and white papers about this topic. I have heard some "rule of thumbs" about ...
0
votes
0answers
52 views

Measured my PCB with Handheld LCR Meter - can you tell me anything?

This is a 5x4cm 8-layer PCB. It has 2 sets of dedicated VCC/GND planes plus ground plane polygons on top and bottom. It is not high speed. The top digital speed is 1Mhz SPI. It has 3 micros running on ...
0
votes
3answers
341 views

Connecting signal to multiple summing amplifiers

For a normal op-amp inverting summing amplifier, each signal is tied to the negative input of the op-amp. Imagine the scenario where I have three signals. In adder 1, I want to sum A and B. In adder 2,...
0
votes
1answer
157 views

Cyclone V data corruption at high frequency

I'm currently trying to implement a FPGA design using a 325 MHz clock, which writes to the SDRAM Controller of a Cyclone V 5CSEBA6U23I7 (Speed Grade 7). When running my IP Core with 2 MHz everything ...
0
votes
2answers
235 views

PL9823 data line corruption when using 3v3

This is my schematic: The PL9823 uses the same protocol as WS1012 (NeoPixel) When using 5V MCU and 5V to power the LED everything works OK. When using 3v3 MCU and 3v3 to power the LED everything ...
3
votes
1answer
61 views

Reflections of Low bit rate signal and High bit rate signal

I was reading wikipedia page on Signal Integrity and got stuck with this paragraph. It says: The channel flight time (delay) of the interconnect is roughly 1 ns per 15 cm (6 in) of FR-4 stripline (...
4
votes
2answers
2k views

Will a 75ohm cable work with (not break) a 50ohm gsm shield?

I need to have a long (100') stretch of cable from my antenna to a GSM box (remote control for heating via GPRS or SMS), and I need to minimize signal loss. In another (totally different) question ...
7
votes
1answer
205 views

USB 3.1 over PCIe board edge connector

I am designing a system with a carrier board that has all of active logic on one board and most connectors on a backplane board. The interface between the two boards is a x16 PCIe board edge connector....