SL2.1A Desktop USB Hub

Working Principle:
This document, CoreChips-SL2.1A.pdf (semiee.com), describes a USB 2.0 hub chip based on the SL2.1A chip
. The SL2.1A uses an SOP16 package; care must be taken to avoid solder bridging during soldering.
The SL2.1A chip has a built-in crystal oscillator. If you forget to buy a crystal oscillator, connect the lower pin of the crystal oscillator pad to GND, as shown in the diagram. However, it is still recommended to use an external crystal oscillator with a frequency of 12MHz.
Similarly, the 3.3V AMS1117 can be left unsoldered, as the chip has a built-in power supply.
The 2-pin Type-C connector is used for auxiliary power; this interface needs to be soldered and connected to a 5V power supply when using high-power devices such as external hard drives.
M4 screw holes are provided around the perimeter for mounting copper pillars, bolts, and other fasteners.
 
All four ports are USB 2.0. Three are front-mounted and side-mounted to reduce PCB space usage. Custom designs can be added to the empty space in the middle of the front USB ports; I've placed a USB logo there. There is also a rear USB port for connecting devices that don't require frequent plugging and unplugging, such as keyboards, mice, and printers. Those who need it can modify the circuit diagram and move it to another location.
Board size: 45mm*99mm (long side is the limit for free-to-use).
All filter capacitors use 0805 specification 104, but larger values ​​or other packages can be used.
 
Custom pattern method:
 1. Open the PCB in LCSC EDA (save as your own document).
 2. Press PG (Place - Image), import the image, and fine-tune the parameters. If necessary, you can use software like Photoshop to preprocess the image.
 3. Hold down Shift and drag the corner points of the image to adjust it to a suitable size.
 4. If you want a regular silkscreen pattern, change the layer to the top silkscreen layer. If you want a tin-plated/immersion gold effect pattern, change the layer to the top solder mask layer and ensure the pattern does not exceed the GND copper area.
 
PCB order parameters:
Double-layer board, 1.6mm board thickness, 1oz copper thickness, solder mask color is arbitrary, immersion gold optional. Other settings are default.
Immersion gold is not mandatory, but it can be used for free. The gold pattern paired with matte black solder mask creates a better effect.