------Question for 750320324 Please Put your question below------
Hello, can I use your -40 C resistant isolation transformer with type number 750320324 at -55 C? What problems can there be with using it? Do you have a -55 C type number or a solution suggestion?
Welcome to the forum.
The manufacturer clearly states it is only rated for operation down to -40°.
So operating it at -55°C means there is absolutely no warranty that it will work or even be safe to try.
Even if a particular part you get works when you test it at -55°C, there will be no guarantee how long the part will operate safely.
As a general rule, when a manufacturer makes the effort to determine an operating temperature range, you are completely responsible for what happens when you use the part outside of that range.
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Thanks your intrest and answer.
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I have another question. This component reduces the 12 volt voltage to 3.3 volts. Can I get a constant 3.3 volts without any voltage rise at the secondary side output and without using LDO?
I think you have chosen the wrong type of transformer for your application. The part you are looking at is a push-pull transformer which is only one of many components required to design a push–pull converter.
https://www.digikey.com/en/products/detail/würth-elektronik/750320324/21822730
When you say 12V and 3.3V, do you mean AC or DC?
For 12VDC to 3.3VDC you want a power supply.
For 12VAC to 3.3VAC I could not find any regular step down transformers readily available and a custom transformer would be very expensive.
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Yes, I mean DC power. I want to design an isolated dc circuit with using power transformer.
The answer to your question should be in the data sheet for U1 and your design calculations.
I can’t find any info on that IC myself so can’t offer any more help.
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Hello, Ramazan.
Transformers like 750320324 are inherently AC devices that don’t really accomplish much with DC voltage. Using it for DC voltage means you don’t really have a transformer, but instead two inductors next to each other on the board that don’t meaningfully interact once the DC current through the primary stabilizes after the circuit energizes.
The type of operation you’re describing, stepping down 12VDC to 3.3VDC, is specifically the domain of voltage regulators. LDOs are simply and easy to implement but lossy; switching regulators are much more energy efficient but noisy. May I ask which specific advantage you’re looking to gain or drawback you’re hoping to avoid in your circuit by using a transformer instead of a regulator?
As well, thank you Paul for your assistance with this one thus far.
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Hi ramazan.tuncel,
Without using a secondary side LDO, you are going to have significant ripple voltage, and the average DC voltage will vary with varying loads. That’s the nature of transformer-based push-pull DC-DC converters. The only means of more carefully controlling the output voltage without using an LDO would be to figure out a feedback mechanism to adjust the input side of the transformer based on feedback from the secondary side. That requires a different type of DC-DC controller which is designed for such an architecture.
We do sell integrated solutions which perform the same task, both fully regulated and unregulated options, which can simplify the design. Here’s a link to some isolated and regulated output DC-DC converters which can take a 12VDC input and give a regulated 3.3V DC output capable of supplying at least 500mA.
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I want to use the transformer for isolation the circuit.Actually you know that for dc dc isolation we have two different way. First , if the circuit is power circuit we use transformer. Second one is signal circuit which we use optoisolator. I hope this will help you to understand better.
Yes, there are suitable products, but unfortunately the -55 c temperature environment does not fit.
İf I heat the component on the pcb ı hope that will work properly. But how can ı increase the temprature from -55 to -40, for this do you have any idea?
Two of the products in the search result from @David_1528 are rated for -55°C.
Here’s that result filtered for -55 to 125°C operating temperature.
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