Need help identifying load switch

[fzabkar]

I need help to identify the 6-pin component marked "AQI" in the following thread:

https://forum.hddguru.com/viewtopic.php?f=1&t=38970&start=20



Identifying the component won't help to fix the problem (corrupt NAND data in an SSHD), but I would still appreciate any assistance so that I can add it to my IC database. The OP has provided voltage measurements which suggest that it is a load switch.

There is a second mystery component which appears to be a 1.2V LDO regulator, but its markings are not discernible.

There is a similar PCB, with a differently marked load switch, in the following thread:

https://forum.hddguru.com/viewtopic.php?f=1&t=29046

Thanks.

[shakalnokturn]

What is the package type?
Can you give any more electrical detail? (1,2 in / 4 out / 3 control)
Are pins 1,2,5,6 linked as they could be for a MOS drain?

[fzabkar]

I know nothing more about this component beyond the OP's feedback in those other threads.

Pins 1 & 2 appear to be the input (+1.8V), and pin #4 appears to be the output (also +1.8V). This component appears to be involved in power management, otherwise I see no point to it. I find it odd that there appears to be a resistor connected in parallel with the capacitor on pin #4, so I'm wondering whether I've got it wrong.

I suppose I could work out the dimensions of the chip by comparing them against the known pitch of the PCB's SATA connector, but that sounds like hard work. :-)

[LateLesley]

OK, I'm not sure I've found the right part, as the datasheet is a 5 pin package, but it does say they come in 6 pin as well. I found this TI LDO with a package marking "AQI".

https://datasheet.octopart.com/TPS71550DCKRG4-Texas-Instruments-datasheet-33012771.pdf

[fzabkar]

The 6-pin (SOT23-6 ?) device is the part which I suspect is a load switch, or maybe a MOSFET operating as a load switch.

There is a 4-pin BGA chip below it which I believe is a 1.2V LDO regulator.

The TPS7515xx parts don't appear to be suitable in either position. Thanks for looking anyway.