Questions tagged [termination]
The matching device placed at the end of a trace that is acting as a transmission line. This termination prevent reflections from the end of the line and ensures a complete transfer of energy in the waveform into the receiving unit.
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MAX3362 RS485 IC connection with ESP32
I am using MAX3362 RS485 serial data transfer IC with ESP32. Marked pins 1, 2 and 3 are connected to GPIOs of ESP32. Do I need to add any additional pull-up resistors or some termination resistors or ...
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Is specific resistor and capacitor material type required for termination of high speed lines on PCB?
Most resistors will be metal film (aka thin film) and most capacitors will be ceramic (class II dielectric). Small components have less parasitive inductance than larger ones.
There are different type ...
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Should I put a termination resistor?
I am a beginner in electronics and am trying to design a PCB where a buffer (BUF634A) output will be connected to an AD8138 (Differential ADC driver). In the PCB's previous iteration, I used a ...
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Expected Outcome of a LVDS Transmitter Output if there's no Termination Resistor
I know this sounds like a silly question, but what would the expected waveform of a LVDS transmitter that has no termination resistor look like? If the expected output were to be a 20 MHz LVDS clock ...
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Drive strength and termination on a 50MHz multi-card backplane bus
I'm helping someone design a spec for a computing ecosystem based on Z80 and Eurocard. One of the challenges is that we want to support modern Z80 chips clocked at up to 50MHz, which means we have to ...
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HCSL source vs. end termination
Regarding HCSL I wonder why there is source termination at all?
If in case of source termination, at receiver side there is no termination or a high impedance input, then the input reflects nearly all ...
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General guidelines to avoid damaging RF components
So, I am a young researcher in physics and use RF components like splitters, mixers, couplers, amplifiers, etc. These are not high voltage amplitudes at all - at most a few volts - often hundreds of ...
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Thevenin termination and RC termination for transmission line
Using series or parallel termination resistor aims to improve signal integrity by reducing reflections caused by discontinuities in the characteristic impedance. This much is clear.
What is not clear ...
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Why does voltage in RS485 bus change significantly when termination resistor is connected?
I've set up the following simple, non-terminated RS-485 network:
The bus is 10m long CAT5e cable, carrying a 4800 baud signal. RS-485 transceiver (TRX) is an XY-k485 module (MAX485-based).
...
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TTL bus termination physical circuit layout
I'm breadboarding a simple data bus terminator for a 1970s TTL computer bus that was normally unterminated. I'm trying both passive and active termination to see how they work, but have a question on ...
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Is this a right magnetics termination for PoE and non-PoE application
I came across the below schematic image while trying to read Bob-smith termination.
Would there be any problems with the termination on the right side with and without PoE?
Can someone explain a ...
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Understanding passive TTL termination
I've been working with 1970s devices and an unterminated system bus. I am adding termination to that but want to first understand a circuit that I have seen to make sure I understand what's going on. ...
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Termination for unused pins on motor controller
I am designing a motherboard for a motor controller.
The motor will be a BLDC motor. I will be using the hall sensor pins on the Motor controller but have no need for several of the features offered ...
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Terminated RC filter
Few days ago I asked in another thread if there was an easier way to get an expression for a transfer function of the circuit shown below in a form H(w)=H(0)*N(w)/D(w).
I wanted an analytical ...
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Buffer for driving VMEbus
I am working on a project where I am reusing a VMEbus backplane to create a bus between some cards of my own design. This backplane has passive termination on both ends.
I am trying to find a buffer ...
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Conducted Emissions for Ethernet ports
A device has a DC power port as well as 2 Ethernet ports. One of the ethernet ports supports PoE++. Basically, the EUT can be powered through PoE.
I have a question regarding Conducted Emissions ...
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CAN FD termination with plugged in modules
Is it possible to use CAN FD in scenario in which there is single main device and additional modules are plugged or hot plugged into each another?
MAIN->MOD1->MOD2->MODn
The main device will ...
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How to determine the rise time to treat if the signal as a transmission line?
I know that If the length of the track is between 1/6 or 1/4 of the effective length of a feature like an edge a system can be regarded as lumped.
BUT A a lot of times, the rise time cannot be taken ...
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Impedance matching 133 MHz - Topology and terminating resistor concerns
I am using the QSPI bus of the RP2040 to talk to a flash chip. I am also putting 8 more chips (PSRAMs) on that bus in my design, and a second RP2040 to load them. The datasheet for the RP2040 isn't ...
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Why is the DDR termination voltage half the supply voltage? [closed]
Why is the DDR termination voltage (VTT) one-half the VDD voltage?
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Is there an antenna problem with CAN Bus selectable split termination header pin?
I am trying to implement a jumper-selectable CAN Bus termination with a SPLIT configuration, as shown in this Analog Devices example:
https://www.analog.com/media/en/technical-documentation/user-...
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RS-485 bias & termination resistors with 3.3v transceiver and 100 ohm cable
I am trying to connect two boards together with a few feet of Cat 5e cable. Both boards will be using 3.3v RS-485 transceivers (ISL83483 or similar).
Using this calculator, I entered 3.3v for supply ...
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How to know whether a differential transceiver is internally terminated for common mode voltage or not?
In a keynote by Rick Hartly titled "What your Differential Pairs Wish You Knew", it is suggested that especially at high speeds, it is necessary to terminate the differential pair not with ...
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SPI bus termination for variable line length / variable number of slaves
There is a lot of information online for SPI bus termination, but my situation is a little bit different. I have created a system with the intention of 'plug and play' IMUs. Although the main ...
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Does SPE (Single Pair Ethernet) require termination?
It is stated that it needs 100 ohm termination resistor but is it end of the each line externally?
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Three-state buffer SPI termination requirements
I have question regarding SPI termination when using three-state buffers:
Do we need termination resistor from master to three-state buffers (since ICs are very close)
If we do, then do calculate the ...
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CAN Bus termination resistor in only 2 device connection
A termination resistor in CAN ( .. or other differential pair communication like RS485 ) is necessary to absorb reflection. The value is related to wire length, electrical frequency, baud rate. It ...
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Novel CAN bus design - needs criticism
I'm designing a CAN bus interface for a PCB I'm working on. CAN and high speed/long distances are new to me, so I have a list of concerns about my design ideas, and I would appreciate someone with ...
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RJ45 termination in fast ethernet
I am working with fast Ethernet. My question is that we are using only two pairs in 100 Mbps.
How will I terminate pin 4 and 5 and pin 7 and 8?
Can I separately terminate magnetic center tap with a 75 ...
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SerDes LVDS termination with isolation
I have the following chain:
There are two FPGAs (Microsemi and Lattice) that I am connecting through LVDS SerDes communication. The two FPGAs have isolated power thus the isolation for the data in ...
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Capacitors on center tap
This is a follow up to a previous question that I asked here
Why do we add capacitors on center taps to the magnetics when connecting to an Ethernet PHY?
Also what is the reason on why we terminate ...
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Tap into CAN bus
I'm thinking about tapping into an existing CAN bus. I'm going to attach in a middle point, and I don't want to introduce any issue in the original bus.
In order not to disturb the original bus with ...
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Bob Smith Termination - Where should we use it? [duplicate]
What is a Bob-smith termination and why do we use it?
I've seen it being using in Ethernet RJ-45 connectors where it is terminated to Chassis ground?
Can someone tell me how this type of termination ...
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How to correctly terminate a TTL line between two ICs?
I am designing a circuit to convert a 5ns ECL signal to an LVTTL signal of >10ns. The SY100ELT25 is used to convert the ECL to 5V TTL which is then fed into the SN74LVC1G123 to further reduce the ...
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Does forward termination of a cable hide the capacitive load?
I stumbled across this claim in the datasheet of the TLV3541 opamp:
The TLV354x output stage is capable of driving standard back-terminated 75-Ω video cables, as shown in Figure 23. By back-...
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USB Data Line Current Value
I am designing USB2.0 hardware input but i don't have enough space on my PCB area. I searched many site but I cant find any information about D+ D- data lines power consumption. I am using 15R ...
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Why do we need to use a 100ohm differential probe to measure ethernet signals when there is not any standard?
I was going through the debugging techniques of ethernet signals and found that we can capture the ethernet signals using a 100ohm differential probe.
Why do we need to add 100ohms on the ...
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DDR3 Termination Resistors and VTT Capacitors
I have a DDR3 implemented in our current design with 50 Ohm 0402 termination resistors and 0.1uF 0402 decoupling capacitors to VTT on the address, data and control lines. The design is working well ...
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CAN bus termination resistor
I'm trying to design a CAN device where the user can select which device is the beginning/end device and activate the 120 ohm resistor accordingly. I've seen some examples using a switch, but I'm ...
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What's the signal seeing on the output - 50 ohm?
Hi, I'm designing an OP amp circuit. I would like to terminate the output with 50 ohm because the device will be a measurement device with an oscilloscope or DUT on the iutput.
Left side is basically ...
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How Does an Adjustable Transistor Size CMOS Driver Work?
Background
The source-terminated reflected wave switching scheme is a familiar one. One just needs to add a source-series terminator, which added together with the driver's output impedance equals the ...
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RIN measurements of a laser
I want to measure the relative intensity noise between 0 and 1 MHz of a laser using a photodiode (20 MHz BW), a voltage amplifier (10 MHz BW), and a spectrum analyzer. Since I don't have so much ...
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Help needed with determining PCB trace termination for µC/SDRAM interface
I am trying to figure out whether I need termination resistors for my PCB routing between a µ-Controller and an SDRAM (IS42S32800J-6BLI) that I plan to clock at 166 MHz. According to Table 72 of ST's ...
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Line termination for single-ended to fully-differential conversion
I am trying to convert a single-ended signal from a sensor to a differential one by using THS4500 from TI. The output of the sensor goes through a buffer before being connected to the fully ...
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ESP-PSRAM64 Termination Resistors
ESP-PSRAM64 uses a bidirectional QuadSPI interface at up to 133MHz. I am connecting this to an STM32 microcontroller. Normally I would use some series termination resistors at the source (e.g. for a ...
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How to terminate branches in a transmission line
some research has unfortunately not led to a clear result. Branches in transmission lines are not desirable, but if they are unavoidable the question arises how to properly terminate the individual ...
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Why is the tip of my PL-259 connector sheared off?
I recently ordered a cable with a PL-259 termination and when it arrived I saw that the tip of the plug had been sheared off and at first I thought it was defective and went to return it or downgrade ...
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Bi-directional Line Termination using series resistor (s)
I am designing a PCB for an ST micro MCU with external SDRAM.
On the demo board, ST is using one(1) series resistor termination for the bidirectional data lines.
ST places this resistor at about 30/70%...
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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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Can a node on a terminated end of a CAN bus self-identify that it is the final node?
Using the example below, is there any way for Node1 or Node3 to be able to recognize that they are the final nodes on the CAN bus? I want to allow my device to automatically enable a 120Ohm ...