Schottky diode with the correct voltage and current rating

  • Thread starter Sid55
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  • #1
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Summary:
Any suggestions on selecting correct voltage and current rating ?

I would like to add a Schottky diode on the output of a boost converter to stop reverse current flow that can handle DC 10-60V up to 12A on the output but with as little voltage drop as possible.
Non-isolated boost converter
Input Voltage: DC8.5V to 50V
Output Voltage: DC10V to 60V
Max. Ouput Current: 12A
Frequency: 150KHz
1569794719560.png
 

Answers and Replies

  • #2
berkeman
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11,892
Summary: Any suggestions on selecting correct voltage and current rating ?

I would like to add a Schottky diode on the output of a boost converter to stop reverse current flow that can handle DC 10-60V up to 12A on the output but with as little voltage drop as possible.

Non-isolated boost converter
Input Voltage: DC8.5V to 50V
Output Voltage: DC10V to 60V
Max. Ouput Current: 12A
Frequency: 150KHz
View attachment 250380
What reverse current flow?

And your input and output voltage ranges are not consistent with a Boost topology converter. Maybe a Sepic or Boost-Buck converter...
 
  • #3
26
1
What reverse current flow?

And your input and output voltage ranges are not consistent with a Boost topology converter. Maybe a Sepic or Boost-Buck converter...
It's a boost converter and it's certainly not a boost-buck converter.
 
  • #5
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'Low forward voltage drop schottky' or 'low VF schottky' is a category on its own: maybe you should try searching with this from the start.
About the voltage: it is based on the actual setup. Serial diodes in the output are often used when more than one sources are powering a common circuit (like a battery and a DCDC in parallel). We need to know the actual circuit - the adjustable output boost converter alone is not enough to give a suggestion.
 
  • #6
berkeman
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Non-isolated boost converter
Input Voltage: DC8.5V to 50V
Output Voltage: DC10V to 60V
It's a boost converter and it's certainly not a boost-buck converter.
So when the input voltage is 50V and the output is 10V, it is still operating in Boost mode?
 
  • #7
Baluncore
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2021 Award
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So when the input voltage is 50V and the output is 10V, it is still operating in Boost mode?
The key word is boost. Input Voltage: DC8.5V to 50V. Output Voltage: DC10V to 60V.
I believe the device illustrated produces Vout > Vin.
So for 8.5 Vin, it can produce from 10 to 60 Vout.
For 50 Vin, it probably produces from about 51.5 to 60 Vout.

The two pot adjustments set the regulated output voltage and the output current limit.

Chinese websites do not know what they sell, so they put catch-words in their listing title to get more hits and more sales. They copy the technical information from other sellers listings.

I just received a full refund from eBay/Paypal on DC converters listed as "buck, boost, step up, step down" when they were buck converters = step down only.
Where the listing may be deliberately misleading it pays a buyer to use eBay, and avoid Ali Express which protects the Chinese seller in a dispute. Caveat emptor.
 
  • #8
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So when the input voltage is 50V and the output is 10V, it is still operating in Boost mode?

It is pulling in the standard 12V DC from my old computer ATX PSU. The boost converter boosted 12V DC to
(maximum) 67.5V on the output.

PSU.jpg
 
  • #9
berkeman
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11,892
It is pulling in the standard 12V DC from my old computer ATX PSU. The boost converter boosted 12V DC to
(maximum) 67.5V on the output.
Okie dokie. So ignore what you posted for specs, got it.

Can you say what your application is? You want a higher voltage for some application, and want to use a standard ATX PSU as the initial voltage source? We can help you figure out how to meet the minimum output current requirements for those PSUs so that your setup will work at lower output currents. Those PSUs have a minimum output current requirement or they shut down.
 
  • #10
rbelli1
Gold Member
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You will want to watch how high you set that voltage. The capacitors from what little is shown of the label appear to be 63V. I would be wary about using them much above 50V for any reason and not much more than 30V if using them in any sort of high temperature environment.

You're lucky they didn't jump right off the board at 67.5V.

BoB
 

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