Questions tagged [digital-isolator]

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2
votes
1answer
44 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 ...
5
votes
2answers
192 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 ...
1
vote
2answers
93 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 ...
0
votes
1answer
55 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(...
0
votes
1answer
118 views

SI8751 isolated mosfet driver and msofet NVD5C668NL

I need help for my very first application with power mosfet The goal is "simple..": create a SSR for switching a generic DC load with variable power supply from 5V to 48V and max 25A. Isolation isn't ...
0
votes
1answer
30 views

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 ...
0
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0answers
122 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 ...
1
vote
1answer
483 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 ...
6
votes
4answers
2k 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 ...
4
votes
2answers
1k 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 ...
0
votes
3answers
270 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 ...
3
votes
3answers
2k 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 ...
0
votes
1answer
125 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 ...
2
votes
4answers
3k 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 ...
1
vote
4answers
1k views

When do we prefer isolator over optocoupler?

Today I have learned that a device called "isolator" exists (eg: SI8712CC-B-IS). Its function is very similar to the optocoupler's. On the good side, it is much much faster. While it is very hard to ...
4
votes
2answers
4k views

RS-485 isolation required?

I would like to confirm my understanding. Suppose I want to have two battery-powered MCUs inside an (unmanned) aircraft communicate with each other via RS-485. If those MCUs are powered from the same ...
4
votes
1answer
261 views

ADuM1301 digital isolator - PCB layout question

We are using the ADuM1301 digital isolator in one of our designs. The PCB layout section from the data sheet states: In applications involving high common-mode transients, care should be taken ...