Author Topic: Is there a single-component high side switch?  (Read 3081 times)

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Offline rea5245Topic starter

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Is there a single-component high side switch?
« on: March 17, 2017, 08:06:27 pm »
Hi,

I want to use a 5V microcontroller to switch up to 12V on and off on the high side of a load. A common way to do this is with an NPN, a P-MOSFET, and a smattering of resistors.

In fact it's so common that I can't help but think there must be an integrated component for it, just as you can buy darlington transistors and pre-biased BJTs. But after poking around on Digi-key for a while, I haven't found such a beast.

Do you know of a component like this?

Thank you,
   Bob
 
 


Offline cyberfish

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Re: Is there a single-component high side switch?
« Reply #2 on: March 17, 2017, 08:18:56 pm »
With 5V logic you can just use a N-MOS and a P-MOS. You can get them in the same package (eg. http://www.aosmd.com/pdfs/datasheet/ao4616.pdf).

Then all you need is a pull-up resistor. If you want the design to be more robust, you can add a gate resistor on the N-MOS to limit peak switching current, but that's not strictly necessary.
 


Online Zero999

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Re: Is there a single-component high side switch?
« Reply #4 on: March 17, 2017, 08:36:53 pm »
What's the maximum current? What voltage drop is acceptable?

If you need lots of channels, then perhaps a high side driver IC will be suitable?

TBD62783A
https://toshiba.semicon-storage.com/info/docget.jsp?did=30523

MIC2981
http://ww1.microchip.com/downloads/en/DeviceDoc/mic2981.pdf

TD62783
http://acg.media.mit.edu/people/simong/hotpants/tech/media/TD62783AF.pdf

M54563P
https://www.mitsubishielectric-mesh.com/products/pdf/m54563p_e.pdf
 

Offline rea5245Topic starter

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Re: Is there a single-component high side switch?
« Reply #5 on: March 17, 2017, 08:43:29 pm »
What's the maximum current? What voltage drop is acceptable?

0.5A max, probably a lot less. When I'm switching 12V, I could live with a 2V voltage drop. I'd also like to switch 5V with no more than a 0.5V drop.

- Bob
 

Offline capt bullshot

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Re: Is there a single-component high side switch?
« Reply #6 on: March 17, 2017, 09:03:36 pm »
What's the maximum current? What voltage drop is acceptable?

0.5A max, probably a lot less. When I'm switching 12V, I could live with a 2V voltage drop. I'd also like to switch 5V with no more than a 0.5V drop.

- Bob
VN750 by STM or ITS4141 / BTS4141 by Infineon should do the job. Check the datasheet for 5V operation, the VN750 might not be suitable for such low voltage
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Offline rea5245Topic starter

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Re: Is there a single-component high side switch?
« Reply #7 on: March 17, 2017, 10:37:19 pm »
Thank you all for your responses. You put me on the right track by showing what keywords and categories I should be looking for. The MIC2514 looks like a good fit for my application: no external components required, switches anywhere from 3V to 13.5V with a logic input, and conducts as much as 1.9A. (http://ww1.microchip.com/downloads/en/DeviceDoc/mic2514.pdf). As Dave would say, Bob's my uncle.

Thank you,
   Bob
 

Offline tecman

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Re: Is there a single-component high side switch?
« Reply #8 on: March 18, 2017, 01:25:43 am »
How about a ULN2987.  Low cost, up to 35 VDC, 500 ma, 8 outputs and OC fault detect/shutdown.  best of all, cheap

paul
 

Offline rea5245Topic starter

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Re: Is there a single-component high side switch?
« Reply #9 on: March 18, 2017, 01:58:06 am »
How about a ULN2987.

That looks good too. But neither Digi-key nor Mouser carry it. That's weird.

- Bob
 

Offline JoeN

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Re: Is there a single-component high side switch?
« Reply #10 on: March 18, 2017, 03:10:53 am »
How about a ULN2987.

That looks good too. But neither Digi-key nor Mouser carry it. That's weird.

- Bob

I think Allegro obsoleted their source drivers.  Micrel still has a very similar one.

http://ww1.microchip.com/downloads/en/DeviceDoc/mic2981.pdf

http://www.digikey.com/product-detail/en/microchip-technology/MIC2981-82YWM/576-1159-ND/771628
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Offline r.vlad

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Re: Is there a single-component high side switch?
« Reply #11 on: March 18, 2017, 09:54:47 am »
Have a look at TPS22810, it requires only an input capacitor, all the other external parts are only required for optional functions (slew rate control / quick output discharge).
It's pretty small and cheap, I found it when I was looking for a way to turn off a 3.3V supply to be able to hardware reset an NRF24L01 with my microcontroller.
vladradoiu.wordpress.com
 


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