sw3516-ip6525 desktop charger

1. Many electronics enthusiasts have many obsolete laptop power supplies or redundant switching power supplies at home. They are of little use, but it would be a pity to lose them. Therefore, we made a desktop charger that uses old laptop power supplies or switching power supplies.
2. This charger is divided into four independent step-down parts, one full-protocol 68w fast charging part using sw3516/3517/3518 and three 18w/35w fast charging parts using ip6515/6505. You no longer have to worry about slow and slow chargers. The charger is not enough
3. sw3516/3517/3518 are the chips that currently support the most protocols. Among them, sw3518 supports almost all protocols, including vivo fast charging protocol. This design uses the sw3516 fast charging chip by default. You can directly use the sw3518 chip instead, because the three chips are completely Pintopin is a replacement, but the number of supported protocols is different.
4. Since the chip supports the pd20v protocol, it can charge the laptop directly, which is more convenient. However, because it can only step down the voltage, if you use a 19v laptop power supply and cannot output 20v, it is best to use a 20-24v adapter for power supply.
5. The board has terminal blocks, 2.0 or 2.5 DC sockets. You need to purchase one or two sockets according to your needs (there are only two kinds in the BOM below, because only two pads are designed, among which 2.0 and 2.5 pads exactly the same)
6. The sw3516/7/8 chip is in a QFN package, so the welding difficulty is slightly higher. It is recommended to use a hot air gun to weld, or use low-temperature solder paste, and then use a soldering iron to heat and weld on the back of the board.
7. The shell can be 3D printed or laser cut by yourself, or you can use the lower half of the pcb file as the shell (see the instructions below the pcb for details)

8. Note: If you use the default settings, there will be a line width drc error, which can be ignored. All line widths in the PCB are in compliance with Jiali Chuang’s board requirements.

   Since there is a QFN packaged chip in the production tutorial, it is recommended to use a hot air gun for soldering. If there is none, you can also use a soldering iron and a heating table or only use a soldering iron for soldering, but be careful that the temperature of the soldering iron is not too high. A temperature of about 350 degrees is better, and there must be reliable grounding. It is best to use a constant current power supply (or dry batteries in series) during testing to prevent welding errors from burning components. It is best to use a more powerful soldering iron for welding capacitors and interface pins, because the entire board is laid out for heat dissipation. Copper, the solder joints produced by low-power soldering iron are not good.

9. Prepare blank boards and components
10. The solder pads are tinned. When the board is placed upright, the left one of the two LEDs on each part is the power indicator, and the right one is the fast charge indicator. You can choose the color according to your preference. Note that the end of the LED with silk screen chamfers corresponds to the LED. The end with the green dot (the soldering iron soldering method is to tin one pad of the chip device, then use tweezers to hold the chip component, solder the tinned end, and use solder wire to solder the other end) (use hot air Please ignore gun paste soldering or oven soldering)
11. Solder the chip (the ip6525 also has a soldering pad at the bottom, so it also needs to be tinned. If you don’t have a heat gun, you can only apply tin on the bottom pad first, then use a soldering iron to heat the back, solder the bottom pad firmly, and then solder the surrounding pads)
12. Soldering is completed (the inductor pad does not need to be tinned, it can be soldered directly from the side)
13. Then there is the most difficult part of the qfn to solder (actually, this part should be soldered first, but it was done wrong). I used the heating table and soldering iron method. If you use a hot air gun, please ignore it. My solder paste did not arrive, so it cannot be used. Use a hot air gun (you can actually use a soldering iron instead of a heating table) to first tin the middle pad (as little as possible, too much may cause a short circuit), then tin the surrounding pins, and heat the back of the board to make the middle tin Melt, align the chips, and put them on. After cooling, take a pointed soldering iron (must be sharp) and directly drag the solder wire around the QFN chip. The flux should be sufficient and the soldering iron should not have static electricity. Finally, it will be enough to see through a magnifying glass that everything is soldered and not connected.
14. Solder the remaining components and you're done.

debug

1. Observe with the naked eye whether there are any short circuits or forgotten places to weld.
2. Constant current power supply, or dry battery, provides low voltage (1.5-5v) to see if there is a short circuit.
3. Then connect the 12v constant current power supply and measure the output value of each part with a multimeter. They should all be about 5v.
4. Make (purchase) a qc3.0 decoy device. What I made:

Circuit diagram (reprinted from Digital Home, link to the original post , if there is any infringement, please contact us to delete it) 5. Turn off k1, plug in the decoy device, turn on k1, and then press the up or down button. At this time, the fast charging indicator light of this part will light up. , up means the voltage increases by 0.2v, and down means the voltage decreases by 0.2v. You can use a multimeter to measure the output voltage. At this time, turn off k1 or unplug the decoder and the voltage returns to 5v. 6. Find some loads and connect them to the circuit. Be careful not to exceed the chip limit value. , to see if it can work stably (there is a problem in this step of my production. The USB part of sw3516 has low load capacity, but the USBC of the same channel has stable load, but the reason has not been found. It is estimated to be the current sampling part of USB in the chip. It was damaged by static electricity during welding, and the current limiting function is not normal. The solution is to connect another USB current-sensing resistor in parallel, and the actual test is normal under heavy load for a long time) 7. Then the shell can be made, the specific shell plan Use your own imagination, you can also use pcb as the shell, a reference has been given in the pcb file

Test video: Link: https://pan.baidu.com/s/1N3gLgrb1_yB4HC51Dh5uBA Extraction code: 5brr

I found that the terminals and capacitance I originally selected were higher than the USB port, and the USB could not be used after adding the shell, so I have modified them.