Questions tagged [differential]

Differential refers to any kind of signaling where the signal information is carried by two or more paths and both are required to properly reconstruct the signal. For example, USB D+ and D-

Filter by
Sorted by
Tagged with
17
votes
4answers
52k views

How do I measure differential signals (like RS-485 or DMX) on an oscilloscope?

I've encountered differential signals in a few places, such as a differential output audio amplifier and now in a project working with DMX which is similar to RS-485. (Here's a similar question about ...
7
votes
3answers
958 views

Are the currents that travel on the outside of coax really “common mode”?

Consider a ladder-line transmission line. Given any currents on the two conductors, we can describe those currents as the current on each conductor individually, or: currents that flow one way on one ...
2
votes
2answers
1k views

Why do we add Resistors on differential op. amp

Why do we use resistors i differential op. amp circuitry where the relation between the resistors is constant?.. Is it only to define the gain, or does it have more to it? The question is linked to ...
7
votes
1answer
669 views

Running JTAG chain over busy backplane

We are busy designing a large system with around four PCBs slotting into a backplane. Each PCB could contain a DSP as well as a large FPGA. We would like to run 2 JTAG chains through the system, one ...
4
votes
2answers
2k views

Op-amp subtractor: problems supplying a fixed base voltage to be subtracted

The context is that of a simple sound-level meter. An electret mike, pre-amp (transistor), amplify with a 386 op-amp, detect the envelope of the waveform, and the output the level to an ammeter. (...
5
votes
3answers
3k views

Using Single Ended Output with Differential Input by Grounding one Input

I am making a frequency generator using the AD9833 (programmed from the PIC16F876). I wish to use a Programmable Gain Amplifier to adjust the signal level before being sent to a power amplifier (...
1
vote
2answers
657 views

Measuring large differential voltage

I have a high voltage power supply for an electron beam system. The voltage regulator is an old analog system that works via a simple comparator and reference signal from a POT. My problem is the ...
4
votes
1answer
3k views

BJT Differential Amplifier-Long Tailed Pair

I am trying to solve this assignment Consider this schematic (the BJT's are in the effective area, with \$\beta=200\$ so as to \$i_e\approx i_c\$). Also \$R_1>>R_E+r_e\$. Define the ...
2
votes
2answers
1k views

ExternalDifferential ADC Values for PIC

I have a temperature sensor design that I'm using as a reference. It takes 2 RTD sensors and reads their values with a Dual Channel 16-bit Differential ADC. The ADC interfaces through the SPI bus. ...
8
votes
2answers
5k views

Is it worth going to so much trouble with Ethernet differential tracks?

I am laying out a PCB containing an Ethernet connector with integral magnetics, and a Micrel KSZ8051MNL Phy. This is for a 100mbps application. In an attempt to reduce EMI, and make the Ethernet data ...
6
votes
4answers
5k views

Why does this current limiter circuit oscillate?

I'm trying to make a 0-25 mA current limiter. I want to take a control voltage of 0-5 V as input and have it control a current of 0-25 mA through a restive load (the restive load may vary between 0-...
3
votes
3answers
3k views

Differential or Single-Ended ADC?

I'm getting to know the Freescale Kinetis L microcontroller. It's ADC has a lot of options, but long story short, it seems like I should be able to get 16-bit resolution in either single ended or ...
2
votes
1answer
251 views

differencing op amp circuit

How would I implement an differencing op amp circuit that performs the operation 5*v1-2*v2 with the op amp power supply being 12vdc? I already tried the basic circuit but I got negative resistance. Is ...
5
votes
1answer
14k views

+ and - meaning in Tx+ and Tx- in cable pairs?

Tx and Rx are required in Computer networking, used in Cat5 or Cat5e or Cat6 cable? What does +(plus) and -(minus) sign mean in cable pairs for RJ45
1
vote
3answers
2k views

Can you sum and difference in a single op-amp?

I want to take two independent differential signals (audio line inputs with unknown properties which may be present or not), remove any common-mode noise from each of them (they could each have ...
5
votes
4answers
16k views

How to specify 100 ohm impedance on a pcb gerber

I've been using Altium for several years when I've needed to designed boards. However it's all been for simple analog designs and never anything too technical. I'm now trying to take a jump into a ...
16
votes
1answer
21k views

How critical is the layout of USB data lines / how does my layout look?

I'm laying out the USB data lines on my board at the moment, and I'm just trying to get an idea of how well off my design is gonna fare. Here are the particulars: 4 layer board (from the top: signal,...
8
votes
2answers
10k views

Impedance Matching Differential Signals

I'm designing a circuit with RFICs using differential signaling. I'd like to keep noise to an absolute minimum. Let's use the mixer (LT5560) as an example. All of the reference schematics match to 50 ...
8
votes
2answers
510 views

Designing my own Bus

This question is further to my previous question: Alternatives to SPI because of EMI. I am toying with the idea of designing my own communication bus. I would be grateful if someone could cast their ...

1
12 13 14 15
16