Electronics > Beginners
Power mosfet to drive high side of the load. Does it exist?
Psi:
+1 for automotive high side driver.
They have a lot going for them.
- They are high side because cars are common ground
- Rated for driving inductive/capacitive loads
- Most use N-channel with tiny built in boost circuit to drive it so have good Rds on
- Logic level digital control, so you don't have to worry about gate drive current.
- They often have extra features that are useful like
- current sense voltage output
- over current shutdown,
- over temp shutdown.
- built in transient protection
- built in reverse polarity protection
- detection of open circuit load.
Example VN5E010AHTR-E
https://www.st.com/content/ccc/resource/technical/document/datasheet/1e/52/ef/e0/cc/90/4e/2e/CD00240716.pdf/files/CD00240716.pdf/jcr:content/translations/en.CD00240716.pdf
There are lots of chips like that to look through.
Check out digikey Product Index > Integrated Circuits (ICs) > PMIC - Power Distribution Switches, Load Drivers
T3sl4co1l:
Low side protected switches are of course very common as well, for when you don't need high side switching. The simplest kind is a self-powered switch with thermal protection, and, not much else really. (Mind, since these are monolithic, they can respond quick enough, thermally -- within fractions of a millisecond. It's sensing externally that kills the response time, waiting for heat to conduct through whole mms of materials.)
Tim
schmitt trigger:
At my company, we manufacture products that go into vehicle applications. For the last decade, we must have sold many hundreds of thousands of products employing those devices.
I can also recommend that you use them.
autotel:
I feel that my question now is very thoroughly answered. Many thanks!
I agree. After reading some of the posts, I decided that it'd become too expensive to make a "custom switch" and not worth it, since my chances of messing it up are high. In a way it makes sense. I know how to program but not too much about the electronics, hence I should think myself as a systems integrator more than as a electronics developer...
I found some really nice options (here in Helsinki there are only so many components I can get on the same day without paying 20 eur. shipping!) such as the VN750PS-E or VN920B5-E, and those that you guys suggested me. They have amazing specs! Lots of protection against things I was not even dreaming.
Then on the other hand, someone sent me these relay boards which you can buy for ~9 euros, and they come with 8 solenoids. It was a bit frustrating that in reality, whatever effort I did, it still would come out as more expensive; the integrated drivers are roughly 0.5 to 2 euro, even in quantities. I know that massive factory stuff like that might not be the best option, however, I am aiming at making the thing as repairable as possible, and relays are easier to find in general than ic load switches. Now I will discuss with the other people involved about the options.
By the way, most my loads are inductive and I am using the diode against inverse current, of course. Most these switch devices have the protection against this stuff any ways.
David Hess:
--- Quote from: T3sl4co1l on June 28, 2019, 01:12:45 am ---Low side protected switches are of course very common as well, for when you don't need high side switching.
--- End quote ---
I have always wished that Franklin had gotten polarity correct making positive ground the standard and therefor high side switches NPN or n-channel.
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