Choosing an alternative Power switch Driver

Thread Starter

MaxWilko

Joined Jun 21, 2021
9
Hi there,
Wondering if anyone can help me.
I have a PCB I need to design out a component as it is not in stock for a couple of years apparently!

The component is: https://www.digikey.co.uk/product-detail/en/texas-instruments/TPS22959DNYR/296-40715-2-ND/4914161

I have tackled problems like this so far but I do not know much about Power Switch Driver components.

If anyone can help point me in the right direction and things to look out for in particular it would be greatly appreciated !
 

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Papabravo

Joined Feb 24, 2006
17,240
You will certainly have a difficult time if you attempt a discrete replacement. The rds(on) of 4.4 mΩ is an ambitious goal for a discrete design because you need to use an N-channel part and you need to create a voltage booster to make sure you have enough gate voltage above the source to turn the device on pretty hard. The soft start may or may not be a requirement.

I would want to ask a TI FAE a couple of questions about the future of the part and about any replacements. then I would begin a search for a replacement. Distributors can often be helpful in this regard.
 
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Thread Starter

MaxWilko

Joined Jun 21, 2021
9
Hi Papabravo, thanks for this. A discrete replacement might be a bit above my capabilities at this point, never say never though.
I have taken your advise and contacted a TI FAE to see if they have anything in stock that could be an alternative with a few changes perhaps.

I can't find anything near 4.4 mΩ rds(on) (only found 90mΩ "equivalent" and can't see how I would deal with the added resistance , I'll let you know how I get on once I know more. Thanks!
 

Irving

Joined Jan 30, 2016
2,308
There are a few alternative parts (70A, 6mOhm) but nothing in a package that small. A discrete solution is at least 4 or 5 active parts.

Do you need the full 15A capability?
 
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Thread Starter

MaxWilko

Joined Jun 21, 2021
9
Thanks @Irving I have no problems changing a footprint on the design if it serves same role in a different package. I don't need full 15A capability. Unlikely to ever go above 300mA on this PCB as it is a shield PCB for an arduino.
The PCB has space for a larger package or discrete design (if I knew how) so space isn't much of an issue.
 

Irving

Joined Jan 30, 2016
2,308
There seems to be huge unavailability and long lead times on all such devices. Have a look at the SLG59M1709 high side switch. It's very similar, 4mOhm, 4Amp, but has a extra feature which is soft start.

Digikey have stock, though Mouser don't at the moment (were expecting 3000 in April!).

Failing that, the NCP45560IMNTWG-H is another option, in stock at both Mouser & Digikey.
 
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Irving

Joined Jan 30, 2016
2,308
Yes I received some counterfeit parts from them also. But - they worked!
I had some high power MOSFETs that looked like they'd been stamped out of tin foil the pins were so soft, didn't solder well, and the markings on the case were all misaligned. Suffice to say every one has failed under test.
 

Thread Starter

MaxWilko

Joined Jun 21, 2021
9
@Papabravo Spoken to TI FAE and the only components they have similar are ones that are also out of stock, they are saying 35 weeks or more lead time. Think I need a new solution.

@Irving this component that you speak of SLG59M1709, it has an extra feature of soft start. Is this the effect you might get using a capacitor to slow the current onset when switched on? Perhaps I could remove the capacitor in my design and use SLG59M1709 with it's inbuilt soft start.

@peterdeco I might try and buy 5 of these, see if they work as a temporary solution.

Thanks everyone
 

Irving

Joined Jan 30, 2016
2,308
@Irving this component that you speak of SLG59M1709, it has an extra feature of soft start. Is this the effect you might get using a capacitor to slow the current onset when switched on? Perhaps I could remove the capacitor in my design and use SLG59M1709 with it's inbuilt soft start.
@MaxWilko Yes, its basically to suppress a high in-rush current to prevent battery protection systems etc. dropping out/browning-out as switch-on. Without knowing how you implemented soft-start I couldn't say, however the SLG59M1709V requires a capacitor between 2nF and 22nF to give between 1 and 9mS of slew rate for 0 -> 5v output.
 

Papabravo

Joined Feb 24, 2006
17,240
Hi Papabravo, thanks for this. A discrete replacement might be a bit above my capabilities at this point, never say never though.
I have taken your advise and contacted a TI FAE to see if they have anything in stock that could be an alternative with a few changes perhaps.

I can't find anything near 4.4 mΩ rds(on) (only found 90mΩ "equivalent" and can't see how I would deal with the added resistance , I'll let you know how I get on once I know more. Thanks!
I'm guessing they get such a low ON resistance by putting multiple devices in parallel on the silicon die. This may prove impractical to duplicate on a PC board.
 

Thread Starter

MaxWilko

Joined Jun 21, 2021
9
Hey guys I know its been a while, but a prototype is being manufactured. In about 5 weeks I will report back and say if was a suitable replacement. Thanks again
 
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