Looking for help identifying a chip on a switch lite. Main board is HDH-CPU-02.
The chip markings are “M28” and “9K”.
Some googling suggests its a MOSFET but I am very unfamiliar with this chip so I wouldn’t even know if this is a good starting point to find a replacement.
Any help is appreciated and thanks for looking.
Chip Location:
Top Image:
Bottom Image:
Hi
did you find out what was this component please ?
Dan
It’s without a doubt a SOT-143 package (the size and shape of the component).
Please triple-check that these MM measurements for SOT-143 match your part
total body long side length- | 2.8-3mm
centers of pins 2,4 - | 1.6 - 2mm
body short side width - | 1.2-1.4mm
my best guess for ID is a " BF909R,215 " dual gate NPN-MOSFET “RF Small Signal MOSFET” this is a obsolete part you cant’ find on digi or mouser and you will need to find a SOT-143-4 N channel MOSFET with a min gate threshold of 0.3v and a
IDSX (drain-source current) VG2 (orward source-gate 2 voltage) -S =4V; VDS(drain-source voltage) =5V;
(RG1 = 120 kΩ)
of
min 12 max - max 20 mA
if you can’t match exactly that current rating, the min can go down, and the max can’t go up.
M, IC markings are for MOSFETs or magnetic and motor-related ICs since I know the switch has no moving parts and doesn’t use magnetic sensors yet; it’s likely a mosfet if it were a Double or Zener Diode or VRM (possible in this package size), it wouldn’t say m.
here are the data sheets pinout
pin1 s, b source
pin2 d drain
pin3 g2 gate 2
pin4 g1 gate 1
my board view shows pin 2 is a ground connection
pin one is attached to a No connect pad and a capacitor( up by the Realtec RMC ALC5639 IC ) and then in series, another SOT-143 part labeled L15 KC whose pin one is connected to the Realtec RMC ALC5639 IC itself on pin 43, 10 and 23
what are you talking about, isnt that a DFN1x1-4 package?
This is likely the same chip
Doesnt look like it on thr pcb scans, on boardview schematic. No center ground pad it could be interchangeable between board revs. The buttom anchor pad on a paclage that small could be left floating or nc
I could be completely wrong on this, so pinch of salt… but I remember a topic years ago related to what I think was the same IC on erista rev, I didn’t delve to deep into it and didn’t finish positively identifying the IC, but think everything was pointing to maybe a ricoh regulator/LDO but again grain of salt, mght be a mosfet like you say, but may be worth drilling down on the ricoh part numbers for this package type to rule it out.
Same here. It could be either it an audio ic, so there are going to be vrms and fets
ALC5639 ic is odd. There is no datasheet or official vendors, for it is completely proprietary. I’m going to have to take apart my own switch to find out.
Is it a problem that the original component is square and the one you quote is rectangular ? will the pins fit the board?
