Questions tagged [digital-isolator]

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Snooping on an IR receiver with a microcontroller [closed]

I have got some PCB that has an IR receiver and processes that signal in a non-relevant way. I would like to intercept or snoop in on that same signal with an ESP8266, without affecting the original ...
Opisek's user avatar
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1 vote
1 answer
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RS232 : dedicated signal ground or common with power ground?

I'm designing the PCB for a robot, where I plan to add some connectors for external RS232 tools (provided by the client). Each connector will provide power (either 24 or 48V, at 5A max) and an RS232 ...
Sandro's user avatar
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Can I force the DD port in the TI ISOUSB111 Isolator to be downstream-facing?

I am new to USB comm. protocol. I am using a TI ISOUSB111 Isolator. The basic setup seems simple enough but it is not working for me as expected, it does not enable recognition of USB devices. I ...
tom54's user avatar
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1 answer
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GND plane under USB Common mode choke

Wanting to remove common mode noise (CMN) from my USB data line (12/1.5 Mbps speeds) I use common mode choke. My layout is shown below. FL4 is the common mode choke (DLW21HN181SQ2L), and IC3 is a USB ...
Christianidis Vasilis's user avatar
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Should there be separate power isolators for CAN and PWM if the PWM driven system is high voltage and noisy?

In this system, suppose the high voltage system does not have isolated ground references. The mcu CAN rx,tx signals and the PWM signal for the HV motor controller are isolated with digital isolators, ...
Asith Warnakulasuriya's user avatar
2 votes
4 answers
620 views

Isolation on RS232 bus

Is there any "simple" way to get (1500V) galvanic isolation on RS232 (just RX and TX)? By isolating, I mean than I have 2 different grounds on each side of the insulation barrier. On side A, ...
Sandro's user avatar
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How to improve ADC reading accuracy from 1mV to 0.1mV or better

I want to read a DC voltage from a battery with 0.1mV resolution or better and send the value to a PLC based in Arduino Mega. I selected an ADS1115 (datasheet here) which has enough resolution to do ...
bardulia's user avatar
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Digital Isolator Layout - Creepage

In the Digital Isolator Design Guide from Ti, there are some PCB Design Guidelines regarding Creepage. In addition to wide isolator packaging, techniques such as grooves can be used to attain a ...
Rev's user avatar
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2 answers
241 views

Isolation on bidirectional I/O pin

On the PCB we are currently designing we have two isolated grounds, one for the sensitive electronics (including a Jetson Orin NX SoM), and one for the outside-facing connections. The difficult part ...
Sandro's user avatar
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3 votes
2 answers
285 views

Isolated DC-DC converter

We have a design in which we need to isolate a communications signal coming from a TTL serial port and going to a DUT sitting on a bed of nails (functional tester). The supply voltage ranges from 2.5 ...
Renaud's user avatar
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Is it mandatory to isolate D+/D- to clean my noisy MIDI power supply

I designed a Piano controller with MIDI synthesizer board which works pretty well but there's noise in the jack output. All my board is supplied by the USB (a typical type B connector). I searched ...
Thibaut Bourgeais's user avatar
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Rpi I2C with I2C isolator

I have a Raspberry Pi 4B and I want to use I2C to communicate with an Xsens MTi-2 sensor. This sensor requires fast mode of I2C and clock stretching. If I connect the Xsens MTi-2 sensor directly to my ...
rotshorts's user avatar
0 votes
1 answer
504 views

Microcontroller digital input isolation using optocoupler

In my project I'm using an STM32F401 controller. I want to provide a digital input to one of its GPIO (3.3 V maximum) pins to read an industrial sensor output. I'm advised to provide isolation between ...
Sahbaz Ansari's user avatar
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1 answer
168 views

Will RGMII work with a small constant delay in the range of 10~20ns on all signals?

Related to this question. An RGMII interface transmitting data at 1Gbps runs with a clock rate of 125MHz, and data is clocked out on both edges. Given that, it would appear that any skew between ...
user4574's user avatar
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Smallest lowest cost way to isolate RGMII signals between devices on the same CCA?

I have a single Gigabit Ethernet line coming out of a circuit card. Access to the line will be shared by two CPUs. To facilitate shared access, the CCA will have an Ethernet switch IC. The switch IC ...
user4574's user avatar
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2 votes
0 answers
106 views

Ringing at input of digital isolator while driving a mosfet with high voltage and current

From a rectified main 230V supply + 4x120µF 400V capacitor, I'm driving a STW40N65M2 mosfet which commutes a big coil. Gate is driven by MCP14A0304T. Gate current is limited by a 30.9 Ohm resistor. ...
Julien's user avatar
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1 answer
254 views

Digital isolator OOK and edge-based encoding supply current consumption

I am reading this article the use of robust digital isolators in the harsh environments of electric motor drives and it says pulse encoding uses more supply current at higher data rates than 10 Mbps ...
MoMoIsBack's user avatar
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1 answer
281 views

Digital inputs for analog switches (analog or digital ground?)

I'm using an analog switch, ADG1434 to switch some filter components in a circuit. My question is about general best practice for the digital signals going to analog switches. The switch is dual ...
JDC's user avatar
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How to isolate both Vcc and gnd?

There are three designs of complementary switches, which means that when the button is closed only one of configurations conducts the current and activates the circuit and the other circuit will ...
elec's user avatar
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2 answers
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Digital isolator capacitor design

I am new to analog design and I need to design a galvanic isolator based upon the edge-based communication** described in digital isolator design guide as a part of a task. How can I start designing ...
MoMoIsBack's user avatar
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1 answer
73 views

How to pass a signal over isolator with only one side powered?

I have a system composed of a 230VAC zone isolated from a human contact zone with a 7.5mm 2k5 space. On the human side there is a dry contact switch: I am searching for a less than 1€ solution to ...
Damezumari's user avatar
0 votes
1 answer
86 views

Did I connect the FT232 with the Digital isolator Data wired the other way?

I think I connected the Data wires from the FT232RL to the USB Isolator ADUM3160BRWZ upside down. I just want to confirm this, Data - of the one should be connected to Data + of the other ? Datasheet ...
Christianidis Vasilis's user avatar
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1 answer
229 views

Digital isolator says it is bidirectional but its block diagram does not follow that statement

I am wondering if ADUM1285CRZ is Bidirectional or unidirectional digital isolator. It says it is Bidirectional, but the block diagram says otherwise. Tha datasheet block diagram shows one direction ...
Christianidis Vasilis's user avatar
1 vote
1 answer
251 views

What does "Default Output State" mean for a digital isolator?

I do not understand the term "Default Output State" of the SI8422AB-D-IS digital isolator. I saw it on this datasheet at page 3: Does it mean "the default output voltage if the input ...
Christianidis Vasilis's user avatar
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0 answers
90 views

DC>DC Isolated Converter (ADuM5401)

I'm in a bit of a quandary as to if I've approached something the right way or if there's an obvious solution I'm missing. (Sorry for lack of schematic, still WIP). Goal: Self-powered isolated USB >...
Whiterat's user avatar
0 votes
1 answer
223 views

Why we need gate drivers and how much they are important in power electronics applications

Generally, there are low, high side, as well as half-bridge and full-bridge gate drivers, existing in the market. I am keen to learn the basics of all such gate drivers in view of power electronics ...
Lucky's user avatar
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2 answers
363 views

Replacing an optocoupler with a more reliable and durable device

I am working on a project where I need to have some sort isolation from a machine sending out highs and lows of 24VDC to 0VDC respectively. I'm using a microcontroller like an ESP32 that works on 3....
DigitalEther's user avatar
1 vote
2 answers
102 views

What does a transceiver like MAX 483 do, especially when it is connected to RS-485?

I cannot understand the principle that the transceiver uses. Why do we need to connect it to RS-485, and how is the data transmitted? I mean how does it transmit the data and why? It is like I cannot ...
velectron's user avatar
1 vote
1 answer
499 views

Simplify this CAN to CAN transceiver circuit?

I currently have a circuit that does this, is there a way to simplify this circuit, ossibly with isolation? Do I need the BJTs? or can I just connect RX to TX and TX to RX then have a CAN to CAN bus ...
flankenStein's user avatar
2 votes
1 answer
894 views

SPI Communication with multiple slaves: Problem on MISO line when both slaves are connected

----SETUP DESCRIPTION---- I'm running SPI Master VHDL code on an FPGA (Spartan 6 - XC6SLX9-3TQG144) with 2 slaves (both ADC122S021). I have one main board onto which I connect the FPGA. The first ADC (...
12brother12's user avatar
3 votes
1 answer
390 views

Should I remove the solder mask from an isolation-barrier?

To be able to fully utilize the isolation properties of digital isolator ICs such as the ISO7731, the PCB must have an isolation barrier that is accoding to datasheets Free from planes, traces, pads, ...
Jake quin's user avatar
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0 votes
1 answer
114 views

Reading isolated multichannel input with voltage drop on all channels

I am building a circuit to read atleast 22 input channels (24 vdc) using an Arduino board which essentially works on 3.3 vdc or 5 vdc. My current setup makes use of 22 PC817 optocoupler. I am sharing ...
DigitalEther's user avatar
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0 answers
38 views

Is it necessary to remove ground on all layers when using isolated DIO

So, I am using uptocouplers and digital isolators for a project connected to a microcontroller GPIO. I removed the ground (ground plane cutouts) under the load side of the components, is it necessary ...
Alex Er's user avatar
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0 votes
2 answers
271 views

Isolation Capacitance (Cio)

How I can find a practical value of CIO barrier capacitance (primary to secondary side) in digital isolators?
Luqman's user avatar
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0 votes
2 answers
113 views

Do digital signal isolators shift the level of the signal

I am using 2 digital signal isolators, the ISOW7841 and the ISO7730. The datasheet does not seem to explicitly say that if a signal coming from the 5V side comes out 3.3V on the other side or vice ...
Jake quin's user avatar
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0 votes
2 answers
448 views

One power supply on a digital isolator

Atmega328P provides logic signals to the AQH1213 solid-state relay to control AC load (contactor). Task: Protect the Atmega328P in case the solid-state relay fails and supplies high voltage to the ...
Delta's user avatar
  • 513
2 votes
1 answer
53 views

Isolator’s (ISO7720) recommended current

I have a design which uses an ISO7720 digital isolator, with a 3.3 V supply voltage. My output load is 500 Ω. Due to area constraints, I’d like to avoid adding a buffer on the output, if I can. The ...
Blair Fonville's user avatar
5 votes
2 answers
2k views

Using optocouplers at the end of a twisted pair

I am designing a dumb "isolation box" that is to sit between a computer and medical data acquisition equipment. The purpose of this box is to inject power and to provide communications and digital ...
Edgar Brown's user avatar
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1 vote
2 answers
736 views

Bidirectional (opto?) isolators for any protocol?

I would like to isolate digital serial communication between 2 circuits. I don't know much about the protocol between two circuits. It is not a common protocol such as SPI or I2C. Shortest pulses are ...
Saren Tasciyan's user avatar
0 votes
1 answer
73 views

Data Path Routing or Switching for AFE circuit

Currently i am making the PCB (for analog front end) for the digitization of some sensors(electro-chemical and photo-ionizations). To simply the things this sensors are giving output in Milli volt(...
Bhautik R.'s user avatar
0 votes
1 answer
272 views

SI8751 isolated MOSFET driver and MOSFET NVD5C668NL

I need help for my very first application with a power MOSFET. The goal is "simple": create a SSR for switching a generic DC load with variable power supply from 5 to 48 V and max. 25 A. ...
diego's user avatar
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0 votes
1 answer
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ADuM140x: power only one side

In my board it may happen to power only one side of the ADuM140x. All the pins on the other one will be completely floating. When the user plugs in a connector also the second side will be powered at ...
Mark's user avatar
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0 votes
0 answers
226 views

Transformer based digital isolator vs Capacitor based digital isolator

Nowadays, digital isolator vendors all argue digital isolators are more superior to optocouplers. And they also argue their product is more superior to others in some aspect. Like TI (produce ...
diverger's user avatar
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1 vote
1 answer
1k views

how to isolate Maxim dallas one wire interface

I would like to isolate my thermocouple amplifier using a adum1200. Given the following illustration of the chip, does this chip allow me bidirectional comms on the same pin? I hooked up power on ...
Ageis's user avatar
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10 votes
5 answers
4k views

Analog isolation vs Digital Isolation

I am designing an ADC front-end circuit that will accept a 230 Vrms mains connection. My goal is to measure the RMS voltage of the mains. Though not really necessary, I think it would make sense to ...
macdonaldtomw's user avatar
4 votes
2 answers
3k views

Bidirectional digital Isolation

I have used digital Isolators before in unidirectional Designs. I am now faced with isolating a bidirectional digital signal line. Specifically I would like to isolate the 2-wire debug interface of ...
KaRu5's user avatar
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0 votes
3 answers
637 views

Relation between collector current and IF current in an optocoupler?

I need to use an optocoupler to drive BJT. BJT will let 10 A current pass. BJT's have commonly 100 - 150 Bf(current gain) so for 10A transmission I need at least 100 mA current draw from the ...
Alper91's user avatar
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3 votes
3 answers
3k views

Optoisolator with Logic Output - How To Use IC Circuit Example?

I'm looking at an Optoisolator with a Logic Output..It's an optoisolator with a Schmitt Trigger on the output. I think the datasheet is a little bare for my comfort level, so I'm looking for some ...
GisMofx's user avatar
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0 votes
1 answer
188 views

Using ADuM3150 for SPI Interface with Arduino

I am trying to use an isolator for SPI communication with the Arduino. I am presently using the ADum3150. You can find the datasheet here. There are some delays associated with this arrangement and ...
rahul's user avatar
  • 3
2 votes
4 answers
4k views

Sensing analog voltage on Arduino without loading the input circuit

I want to design a voltage divider for my Arduino Analog input pin, to be able to sense the change in voltage in a 9V, 250mA circuit (without loading it). Ive programmed the Arduino so that as soon ...
Ameya's user avatar
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