Leading the way in minimalist, cost-effective, and compact expansion dock

1. This project selects the low-cost and simple SL2.1A main control chip, which has a built-in crystal oscillator (an external crystal oscillator is recommended for stability) and supports 4 outputs. The chip costs approximately 1.5 yuan, and the unit price of other components does not exceed one yuan, for a total cost of about 5 yuan.
       This chip uses STT technology and a single power supply. The chip's supply voltage is 5V, and it integrates a 5V to 3.3V converter internally, requiring only the addition of a filter capacitor to the external power supply. The chip has a built-in reset circuit, and its low-power technology makes it even more outstanding. The chip can use an external crystal or an internal crystal. If using an internal crystal, the chip's XI input needs to be grounded. - Perfectly supports USB 2.0 High Speed ​​(480MHz), USB 2.0 Full Speed ​​(12MHz), and Low Speed ​​Mode (1.5MHz) - Integrated 12MHz crystal oscillator - Integrated 12MHz-to-480MHz PPL (Phase Lock Loop) - Employs Single Transaction Translator (STT) technology, the most cost-effective and efficient solution in the *TT series - Supports automatic enumeration switching from self-powered to bus-powered
- Supports the standard BC1.2 charging protocol
- Port ESD capability is ±4KV (HBM)
2. To accommodate older products, it is compatible with Type-C and Micro-USB as inputs, and a 5.1K port is matched for Type-C to support C-to-C cable communication.
3. This design includes top and bottom covers, eliminating the need for a separate outer shell. The middle section is grooved; after board fabrication, the splicing parts are cut and then fixed using pre-drilled 3mm screw holes. (The 3D printed outer shell design file drawn in SolidWorks will be uploaded later.)