SM Switching Regulator Identification

[Mike Warren]

I have a couple of Seagate portable hard drives, both have a dead SM buck switching regulator that I am not having any luck Googling.

It's in a SOT23-6 package.

The Markings are FF7RNF and FF7IBT so I'm guessing the IC type is the FF7 and the other 3 characters are the batch.

There are 3 of these chips in each unit, which helped me confirm that one in each unit was dead. I'm guessing a power spike killed them. By swapping a good one in one board to the other board got it working perfectly.

The values in the schematic below are what I measured in circuit.

[fzabkar]

I have a database of HDD/SSD ICs:
http://www.users.on.net/~fzabkar/Datasheets/DATAURLS.HTM

If your device isn't listed, you could examine photos of the same PCB in case they have equivalent parts.

Am I correct in thinking that this component is on the USB-SATA bridge PCB?


Edit: This looks like it might be a good fit, but its FB voltage is 0.6V whereas your circuit would suggest that it should be 2.5V.

VB9113, VBCSEMICON Technology, 3A, 4.5V - 21V Input, 500kHz, marking FF7, SOT23-6:
http://www.vbcsemicon.com/upload/pdf/VB9113-v3.0.pdf


Here is another 0.6V candidate:

FR8205, Fitipower, 18V, 3A, 500KHz Synchronous Step-Down DC/DC Converter, marking FF7, SOT23-6:
https://datasheet.lcsc.com/szlcsc/Fitipower-Integrated-Tech-FR8205S6CTR_C172764.pdf

https://www.aliexpress.com/item/1005001992210575.html

[Mike Warren]

Thanks for your reply.

Am I correct in thinking that this component is on the USB-SATA bridge PCB?

Yes.

Edit: This looks like it might be a good fit, but its FB voltage is 0.6V whereas your circuit would suggest that it should be 2.5V.

VB9113, VBCSEMICON Technology, 3A, 4.5V - 21V Input, 500kHz, marking FF7, SOT23-6:
http://www.vbcsemicon.com/upload/pdf/VB9113-v3.0.pdf


Here is another 0.6V candidate:

FR8205, Fitipower, 18V, 3A, 500KHz Synchronous Step-Down DC/DC Converter, marking FF7, SOT23-6:
https://datasheet.lcsc.com/szlcsc/Fitipower-Integrated-Tech-FR8205S6CTR_C172764.pdf

Thanks. They are closer than anything I found. I'll go back and check the feedback resistors again in case I made a mistake.
 

[Mike Warren]

Yes, I did make a mistake. The feedback voltage is 0.6V.

The trick now is to find somewhere to buy them. Mouser, Digikey, E14, RS and Alibaba have no matches for either one and Google thinks one of them is a pair of cowboy boots and the other is a Ryanair flight.

Edit: I see you updated your post with an AliExpress link. Thanks.

Edit 2: Purchased. $44 for FedX shipping! Ouch!

[fzabkar]

It would have been far cheaper to purchase a generic enclosure???

[Mike Warren]

It would have been far cheaper to purchase a generic enclosure???

Then my OCD would be aggravated that my stack of backup drive weren't the same type.

[Mike Warren]

Hmmm.

When I placed the order, 5 days ago, there was a counter that said the order would be automatically cancelled if it was not shipped within 7 days.

I just checked and the order is still not shipped, but the counter now says the seller has 5 days and 2 hours to ship. Looks like AliExpress must be working to a different clock.

I've only bought a couple of things from AliExpress and they both went fine, but this does not inspire confidence.

Edit: Ah, found another place where the days are specified as "business days". That's not stated anywhere near the countdown clock.