Is there a single-component high side switch? - Page 1
Forum section: electronics / projects

author: rea5245
author_rank: Frequent Contributor
timestamp: March 17, 2017, 08:06:27 pm
content: 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

author: MagicSmoker
author_rank: Super Contributor
timestamp: March 17, 2017, 08:16:20 pm
content: Here's a search on digikey for what you are looking for:http://www.digikey.com/products/en/integrated-circuits-ics/pmic-power-distribution-switches-load-drivers/726?k=&pkeyword=&pv7=2&pv7=6&FV=3fc007b%2Cffe002d6%2C1f140000&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25

author: cyberfish
author_rank: Regular Contributor
timestamp: March 17, 2017, 08:18:56 pm
content: 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.

author: Benta
author_rank: Super Contributor
timestamp: March 17, 2017, 08:22:42 pm
content: Infineon PROFET:http://www.infineon.com/cms/en/product/power/smart-low-side-and-high-side-switches/high-side-switch/channel.html?channel=5546d4624d6fc3d5014d9f398efd562f

author: Zero999
author_rank: Super Contributor
timestamp: March 17, 2017, 08:36:53 pm
content: 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?TBD62783Ahttps://toshiba.semicon-storage.com/info/docget.jsp?did=30523MIC2981http://ww1.microchip.com/downloads/en/DeviceDoc/mic2981.pdfTD62783http://acg.media.mit.edu/people/simong/hotpants/tech/media/TD62783AF.pdfM54563Phttps://www.mitsubishielectric-mesh.com/products/pdf/m54563p_e.pdf

author: rea5245
author_rank: Frequent Contributor
timestamp: March 17, 2017, 08:43:29 pm
content: Quote from: Hero999 on March 17, 2017, 08:36:53 pm0.5A 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

author: capt bullshot
author_rank: Super Contributor
timestamp: March 17, 2017, 09:03:36 pm
content: Quote from: rea5245 on March 17, 2017, 08:43:29 pmVN750 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

author: rea5245
author_rank: Frequent Contributor
timestamp: March 17, 2017, 10:37:19 pm
content: 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

author: tecman
author_rank: Frequent Contributor
timestamp: March 18, 2017, 01:25:43 am
content: How about a ULN2987. Low cost, up to 35 VDC, 500 ma, 8 outputs and OC fault detect/shutdown. best of all, cheappaul

author: rea5245
author_rank: Frequent Contributor
timestamp: March 18, 2017, 01:58:06 am
content: Quote from: tecman on March 18, 2017, 01:25:43 amThat looks good too. But neither Digi-key nor Mouser carry it. That's weird.- Bob

author: JoeN
author_rank: Frequent Contributor
timestamp: March 18, 2017, 03:10:53 am
content: Quote from: rea5245 on March 18, 2017, 01:58:06 amI think Allegro obsoleted their source drivers. Micrel still has a very similar one.http://ww1.microchip.com/downloads/en/DeviceDoc/mic2981.pdfhttp://www.digikey.com/product-detail/en/microchip-technology/MIC2981-82YWM/576-1159-ND/771628

author: r.vlad
author_rank: Newbie
timestamp: March 18, 2017, 09:54:47 am
content: 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.