linx12x64 sot-23 5 voltage regulator question

[Thedan55]

hi everyone. i am new to posting here so ill try my best to be as descriptive as possible.

i have 2 linx12x64 windows tablets in for repair. both need usb replacements. one had such a damaged port that it must have caused a spike that burnt the regulator. (ill attach an image) the regulator has "QW6SB" labelled on it.

i did a bunch of research, and while i could not find an exact match, i did find a sot-23 3 that matched my needs....

QW MCP809T-475I Microchip Technology
SOT-23 Voltage detector IC
4.625V+150mV, -Reset PPO

considering its a micro usb port and the tablet is rated at 5v2a i think this does make sense. i will be looking for a sot-23 5leg variant, but i just wanted to make sure im on the right track.

ive looked through digi key, but im quite new to finding parts like this so sifting through the results is a little difficult and confusing.

https://www.digikey.co.uk/en/product...HliVoqAYxDjxQA

these are the results i tried to narrow down in digikey. but i dont know what the min/max voltages etc are supposed to be.

if someone could give me some pointers i would appreciate it.

all the best

immy

[mon2]

Re: linx12x64 sot-23 5 voltage regulator question

Hi. No, this part will not be a voltage detector unless you know this from the schematics?

A voltage detector is a reset supervisor IC that will check for a specific voltage value (threshold) to be reached. The output (reset signal) is often a logic LOW during the rise of the voltage being monitored. Once the voltage threshold is reached, the output is released = high impedance and an external pull-up resistor performs a soft high on the reset line.

Then the CPU starts to do its job.

Rather, suspecting that this fried component is a USB load switch. Still SOT23-5.

There are many vendors including Microchip, Diodes Inc.

Before going there, any schematics available for this board?

Does this component mate with the VBUS line of the USB connector? If yes, then for sure it is a current limited load switch for USB 2.0 use.

[SMDFlea]

Re: linx12x64 sot-23 5 voltage regulator question

the regulator has "QW6SB" labelled on it.

It could be a Silergy SY6280A .Can you post the motherboard part number

https://www.badcaps.net/forum/showpo...1&postcount=12

SY6280/SY6280A Datasheet https://cdn.badcaps-static.com/pdfs/...3e2de12517.pdf
.

[Thedan55]

Re: linx12x64 sot-23 5 voltage regulator question

Hi. No, this part will not be a voltage detector unless you know this from the schematics?

A voltage detector is a reset supervisor IC that will check for a specific voltage value (threshold) to be reached. The output (reset signal) is often a logic LOW during the rise of the voltage being monitored. Once the voltage threshold is reached, the output is released = high impedance and an external pull-up resistor performs a soft high on the reset line.

Then the CPU starts to do its job.

Rather, suspecting that this fried component is a USB load switch. Still SOT23-5.

There are many vendors including Microchip, Diodes Inc.

Before going there, any schematics available for this board?

Does this component mate with the VBUS line of the USB connector? If yes, then for sure it is a current limited load switch for USB 2.0 use.

hi thanks for the response. i measured the vcc pin from the usb to that componant and it does indeed connect to it! thats fantastic.

i tried looking for some schematics but i couldnt find any, i must not be looking correctly, but i did try.

[Thedan55]

Re: linx12x64 sot-23 5 voltage regulator question

It could be a Silergy SY6280A .Can you post the motherboard part number

https://www.badcaps.net/forum/showpo...1&postcount=12

SY6280/SY6280A Datasheet https://cdn.badcaps-static.com/pdfs/...3e2de12517.pdf
.

thats incerdible, ive saved that thread for future use! im not too sure which one is the part number, so ive attacthed a picture of the board. the ins andouts match what im measuring on the current one. i think youve hit the nail on the head!!

hopefully one day ill know how to identify and measure correctly.

i can only find them on amazon

[mon2]

Re: linx12x64 sot-23 5 voltage regulator question

There are many suitable replacements. The Silergy part appears to have a resistor feature to define the max current level for this load switch. However, for USB 2.0, the max current should be 500mA = 0.5A.

Respectively, there are fixed current limit load switches on the market such as:

(you need ACTIVE HIGH for the ENABLE pin)

AP2151WG-7

https://cdn.badcaps-static.com/pdfs/...d79531dcde.pdf

see here:

https://www.diodes.com/part/view/AP2...roduct-options

[SMDFlea]

Re: linx12x64 sot-23 5 voltage regulator question

The Silergy part appears to have a resistor feature to define the max current level for this load switch.

The datasheet is a bit confusing it has a SY6280 and SY6280A but lists both parts as A for the ordering information:
SY6280AAC , SY6280AAAC

SY6280AAAC is the right part number. The SY6280AAAC doesn`t have the discharge mosfet

COxyz for SY6280 (Device code: CO, x=year code, y=week code, z= lot number code)
QWxyz for SY6280A (Device code: QW, x=year code, y=week code, z= lot number code)
.

[Thedan55]

Re: linx12x64 sot-23 5 voltage regulator question

There are many suitable replacements. The Silergy part appears to have a resistor feature to define the max current level for this load switch. However, for USB 2.0, the max current should be 500mA = 0.5A.

Respectively, there are fixed current limit load switches on the market such as:

(you need ACTIVE HIGH for the ENABLE pin)

AP2151WG-7

https://cdn.badcaps-static.com/pdfs/...d79531dcde.pdf

see here:

https://www.diodes.com/part/view/AP2...roduct-options

thank you so much for the help. genuinely appreciated!

do i need to modify the thread title to indicate that my question has been solved?

[SMDFlea]

Re: linx12x64 sot-23 5 voltage regulator question

thank you so much for the help. genuinely appreciated!

do i need to modify the thread title to indicate that my question has been solved?

You can`t modify the thread title,but post again if you have any more problems or you fix them with the new IC`s

[Thedan55]

Re: linx12x64 sot-23 5 voltage regulator question

There are many suitable replacements. The Silergy part appears to have a resistor feature to define the max current level for this load switch. However, for USB 2.0, the max current should be 500mA = 0.5A.

Respectively, there are fixed current limit load switches on the market such as:

(you need ACTIVE HIGH for the ENABLE pin)

AP2151WG-7

https://cdn.badcaps-static.com/pdfs/...d79531dcde.pdf

see here:

https://www.diodes.com/part/view/AP2...roduct-options

quik update. thank you very much for all the help. part arrived the other day, replaced the ic and the damaged usb port and its all working great.

i have noticed one thing thats different from the other tab, it charged great then something happed and it would only charge at .5a, forced a shutdown and then plugged charger in and it was back to charging at 2a.

thanks again!!

[mon2]

Re: linx12x64 sot-23 5 voltage regulator question

On the other ports using this same usb current limit switch, what is the resistor value on pin #3 ?

The max current limit = 6800/Resistor on pin #3 (ohms).

Based on the max current limit value, you can use a fixed limit switch with a similar max value - rather than 500mA.

[Thedan55]

Re: linx12x64 sot-23 5 voltage regulator question

On the other ports using this same usb current limit switch, what is the resistor value on pin #3 ?

The max current limit = 6800/Resistor on pin #3 (ohms).

Based on the max current limit value, you can use a fixed limit switch with a similar max value - rather than 500mA.

its all put back together and once i used an anker cable they both charged at full whack 2a. with almost every other cable it would only get to abot .98 -1a, if i get a chance ill open it up again and measure it.

youll have to pardon my ignorance as im still really learning. in the datasheet it stsates pin 3 has a 10k resistor? i dont understand.

is the current limit value the limit of charging or the limit to enable the switch?

[mon2]

Re: linx12x64 sot-23 5 voltage regulator question

On the original part, pin #3 defines the max current this switch will pass through before turning off. The original part used a resistor to define the max current. The ic datasheet offers details on how the resistance value is linked to the current value. We decided to apply a fixed current load switch that is max current of 500 mA which is typical for a usb 2.0 port. 900 mA for usb 3.0 port with purple insulator. On the fixed current part, the external resistor is ignored but is ok since we are using the same pin out as the original.

What is the load of your usb port?

Do note that the charging current can be selected by the usb cable. Anker likely has other identifiers / components to extract higher current out of your usb port. Sometimes, the cables will use resistor values on D+ and D- pins to define the charge current. If these are missing on other cables, the charge time will be longer.

[Thedan55]

Re: linx12x64 sot-23 5 voltage regulator question

On the original part, pin #3 defines the max current this switch will pass through before turning off. The original part used a resistor to define the max current. The ic datasheet offers details on how the resistance value is linked to the current value. We decided to apply a fixed current load switch that is max current of 500 mA which is typical for a usb 2.0 port. 900 mA for usb 3.0 port with purple insulator. On the fixed current part, the external resistor is ignored but is ok since we are using the same pin out as the original.

What is the load of your usb port?

Do note that the charging current can be selected by the usb cable. Anker likely has other identifiers / components to extract higher current out of your usb port. Sometimes, the cables will use resistor values on D+ and D- pins to define the charge current. If these are missing on other cables, the charge time will be longer.

i see. thats very interesting! this tab states that its rated at 5v2a. so the switch allows an initial current of 500ma to make sure all is safe before allowing it to switch over to charge at a higher rate? or am i getting that wrong?